Of course. Simply look at how Win32::LongPath does it and do it the same way in your own script. This kind of lift-and-drop coding is a great waste of time compared to simply installing the module but since your employer makes the rules they will surely be happy to pay for your time.
Other alternatives include:
- Don't use Windows
- Change employer
- Tap your employer gently on the head with a copy of The Mythical Man-Month until they realise that CPAN is one of Perl's greatest strengths and not something to be shunned out of fear or suspicion