I would move the zip file to the UNC path first (less network bandwidth) and have something on that computer unzip it.
Probably too much work for something simple, actually.
Look at the various Win32::* modules to see which ones can help you with UNCs. I've not had a problem in current versions of Perl, but years ago when working on a project to transfer files between Windows NT and Novel NetWare 3 servers I had to use something that manually mapped drives before copying (because UNCs didn't work on ancient ActiveState Perl back then) and then unmapped when it was done.
