Do you mean how can you connect to the database from Perl without DBI?
The reason I ask is that depending on your work set-up, many people connect from their desktop using a database client tool like Toad for Oracle or DbVisualizer. Then they do their Perl work on a work server of some sort that has the proper modules installed and configured.
There are various ways to run the code from Perl modules without installing it in the usual admin-protected areas.
But before going down that road I would ask if this is a work computer and you need to use Perl and DBI to do some of your work, is there any way to can get the proper permissions to configure your work environment?