Thank you for your answer. It is not exactly what I am looking for but it gives me ideas even if they do not work. I still try.
Code:
<p><strong>Fill the following table with proposal of the drop down menu</strong>.</p>
<p><em>You can fill the transportation, build-up area and (semi-)natural lines only (corresponding unfilled sublines will be considered taken the same values) or fill the sublines too (one or several cells) to distinguish values.</em>></p>
<p>For instance, <em>interest groups</em> can be partially involved about the development of <em>build-up area</em> but you can specify that they are always involved <em>about industrial activity</em> and <em>commerce/services</em>.</p>
<script type="text/javascript" charset="utf-8">
$(document).ready(function(){
// Insert new dropdown values
$('#question{QID} .answer_cell_SQ001 option[value=0]').text('not involved');
$('#question{QID} .answer_cell_SQ001 option[value=1]').text('partially involved');
$('#question{QID} .answer_cell_SQ001 option[value=2]').text('always involved');
$('#question{QID} .answer_cell_SQ002 option[value=0]').text('not involved');
$('#question{QID} .answer_cell_SQ002 option[value=1]').text('partially involved');
$('#question{QID} .answer_cell_SQ002 option[value=2]').text('always involved');
$('#question{QID} .answer_cell_SQ003 option[value=0]').text('not involved');
$('#question{QID} .answer_cell_SQ003 option[value=1]').text('partially involved');
$('#question{QID} .answer_cell_SQ003 option[value=2]').text('always involved');
$('#question{QID} .answer_cell_SQ004 option[value=0]').text('No practice in ');
$('#question{QID} .answer_cell_SQ004 option[value=1]').text('Short-term experience in ');
$('#question{QID} .answer_cell_SQ004 option[value=2]').text('Long-term experience in ');
$('#question{QID} .answer_cell_SQ005 option[value=0]').text('was not achieved');
$('#question{QID} .answer_cell_SQ005 option[value=1]').text('was partially achieved');
$('#question{QID} .answer_cell_SQ005 option[value=2]').text('was fully achieved');
$('#question{QID} .answer_cell_SQ006 option[value=0]').text('was weak');
$('#question{QID} .answer_cell_SQ006 option[value=1]').text('was medium');
$('#question{QID} .answer_cell_SQ006 option[value=2]').text('was strong');
// Define rows to have default answers
var defaultedRows = [2,3,5,6,7,8,9,11,12,13];
var mainRows = [1,4,10];
var firstGroupRows = [2,3];
var secondGroupRows = [5,6,7,8,9];
var thirdGroupRows = [11,12,13];
// Loop through all "defaulted" rows and set default answers
$(defaultedRows).each(function(i, value) {
// Column 1
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(0)').val(3);
// Column 2
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(1)').val(3);
// Column 3
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(2)').val(3);
// Column 4
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(3)').val(3);
// Column 5
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(4)').val(3);
// Column 6
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(5)').val(3);
});
// Loop through all "main" rows and hidden value
$(mainRows).each(function(i,value) {
// Column 1
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(0) .answer_cell_SQ001 option[value=3]').text('').hide();
// Column 2
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(1) .answer_cell_SQ002 option[value=3]').text('').hide();
// Column 3
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(2) .answer_cell_SQ003 option[value=3]').text('').hide();
// Column 4
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(3) .answer_cell_SQ004 option[value=3]').text('').hide();
// Column 5
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(4) .answer_cell_SQ005 option[value=3]').text('').hide();
// Column 6
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(5) .answer_cell_SQ006 option[value=3]').text('').hide();
});
// Loop through all "first group" rows and hidden value
$(firstGroupRows).each(function(i,value) {
// Column 1
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(0) .answer_cell_SQ001 option[value=3]').text('as transportation infrastructure');
// Column 2
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(1) .answer_cell_SQ002 option[value=3]').text('as transportation infrastructure');
// Column 3
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(2) .answer_cell_SQ003 option[value=3]').text('as transportation infrastructure');
// Column 4
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(3) .answer_cell_SQ004 option[value=3]').text('as transportation infrastructure');
// Column 5
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(4) .answer_cell_SQ005 option[value=3]').text('as transportation infrastructure');
// Column 6
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(5) .answer_cell_SQ006 option[value=3]').text('as transportation infrastructure');
});
// Loop through all "first group" rows and hidden value
$(secondGroupRows).each(function(i,value) {
// Column 1
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(0) .answer_cell_SQ001 option[value=3]').text('as build-up areas');
// Column 2
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(1) .answer_cell_SQ002 option[value=3]').text('as build-up areas');
// Column 3
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(2) .answer_cell_SQ003 option[value=3]').text('as build-up areas');
// Column 4
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(3) .answer_cell_SQ004 option[value=3]').text('as build-up areas');
// Column 5
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(4) .answer_cell_SQ005 option[value=3]').text('as build-up areas');
// Column 6
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(5) .answer_cell_SQ006 option[value=3]').text('as build-up areas');
});
// Loop through all "first group" rows and hidden value
$(thirdGroupRows).each(function(i,value) {
// Column 1
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(0) .answer_cell_SQ001 option[value=3]').text('as (semi-)natural areas');
// Column 2
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(1) .answer_cell_SQ002 option[value=3]').text('as (semi-)natural areas');
// Column 3
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(2) .answer_cell_SQ003 option[value=3]').text('as (semi-)natural areas');
// Column 4
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(3) .answer_cell_SQ004 option[value=3]').text('as (semi-)natural areas');
// Column 5
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(4) .answer_cell_SQ005 option[value=3]').text('as (semi-)natural areas');
// Column 6
$('#question{QID} tr.subquestion-list:eq('+(value-1)+') select:eq(5) .answer_cell_SQ006 option[value=3]').text('as (semi-)natural areas');
});
});
</script>
