If you are root, you can add an @inc path to the /etc/profile aswell, so the path will be set for every user after booting.
The entry could look like this:
PERL5LIB="${PERL5LIB}:/home/snadra/my_modules"
export PERL5LIB

The problem is, this does not work with CGI, it is only recommandable for people who don't use CGI.
You need to set $PERL5LIB then inside of the httpd.conf aswell, I think, but I have not tried that yet.

Edit:
I am using a symbolic link now. I put that link into one of the @inc paths.
This is working recursively under Linux, so I can call my modules like:
use Linked_Dir::Dir::Module;