We need to input answer codes with more characters than our current template allows and we also need to include decimals. How can we do this?

Hello and welcome,
You have just discovered one of the major known limit of LimeSurvey... There is a strict format for answer and question codes.
IMHO the direct result is that LS can't be used (without some additional development) in a lot of projects where ID codes and interoperability matter. A bit tricky in 2016 but I understand perfectly that this issue is very difficult to handle

BTW, I posted here a kind of workaround. For me it's now OK about all of this and I hope it may helps you too.

We can use export plugin to export question code/answer code the way we want.