As marto say to you, you can always install your version of Perl (5.8.0, if you need it) and you can run the scripts with that version.
It is really simple, and you can do it as user (no need to be root).
You have to download the Perl sources, and then:

./Configure -des Dprefix =/your_path
make all
make test
make install


Then you can run your script with /your_path/bin/perl yourScript.pl

UPDATE: Naturally, with this method you can test the perl versions you prefer, also the most recent.
In addition you can run multiple perl installations on your system.