CPanel has a internal script for using CPAN to install Perl modules. Learn it and love it:

/scripts/perlinstaller

Most common Perl modules can be installed from WHM ~> Install a Perl Module, or from command line. If you don't know the name of the Perl module you're installing, you may want to use the WHM installer instead, as it has a search feature and its usage is pretty self-explanatory.

For command line installations, pass the name of the perl module (case-sensitive) to the installer like so:

/scripts/perlinstaller MD5

/scripts/perlinstaller IO::Compress::Base

If the module is already installed and you need to update or reinstall it, pass –force:

/scripts/perlinstaller –force MD5

Since cPanel 11, you can now also allow your users to install their own perl modules locally in /home/$user/perl (which is automatically added to their Perl module path) so they don't have to bug you when they need a Perl module, nor to they need SSH access.  You can enable this in WHM ~> Module Installers ~> Perl Module [Manage] . You do need to have compilers enabled for users though, which can be done in WHM ~> Security Center ~> Compilers Tweak .