Just know that string eval can be costly (starts a new Perl interpreter) and potentially dangerous (you aren't using tainted user input to build this string are you?; run this with perl -T to find out for sure).

Are you running this under use strict;? If so, then you will have some problems with my @returnsting. Specifically, you will need to have @returnstring declared before your eval to use it later. That means when you eval "my @returnstring = ...", you will create lexical variable within the scope of the eval that will mask the @returnstring that you declared outside of the eval scope. To solve this, simply remove the my from the string that you build.