You can also use a small script to set the perl path explicitly in the files before running on each environment. At least, for testing purposes - I would recommend keeping the production path in the files that are in version control.

For example, here's a quick version that would replace the #!/path/to/perl line at the top of each file with a path that you pass in:

#!/bin/sh
PERL=$1
for file in `find . -name '*.pl'`
do
    perl -i -ape 's/^#!\s*(.*perl)\s*(.*)$/#!$ENV{PERL} $2/;' $file
done
[download]

I have a script similar to this that I use to increment the release version in all the 'configure.in' files in our release packages at work, so I think this might help you out.