can i get queryString parameter and display it in welcome page on the survey
ex : queryString name Sayhi = Hello and display in highlights

You can try to add a text question with question code "Sayhi" and use {Sayhi} as a placeholder. But I can't say for sure if this works because the question is placed after the welcome screen.
Just test and report back.

Hi,

Surely can be done with js : inspiration for testing :
- www.nsftools.com/misc/SearchAndHighlight.htm
- www.the-art-of-web.com/javascript/search-highlight/
- johannburkard.de/blog/programming/javasc...g-jquery-plugin.html

The url can be parsed in javascript too OR this can be done via a plugin to parse it.

Denis