I don't think you'd be able to upload using that name, since someone else has already reserved the namespace. While it's possible to try to contact the original developer/maintainer, that wouldn't necessarily solve your problem because people may be using that module. Suddenly replacing it with an entirely different one would break their software. IIRC, CPAN recommends reserving the name first, then developing and uploading the module. Also, they recommend running it by some Perl-based groups first (PM, comp.lang.perl.modules, etc.) to get some input. Among other things, you might get ideas for useful names. You might also be told about existing modules that already do what you propose, etc.
Update: Thanks to grinder for pointing out that there isn't a reservation of namespace on CPAN; that people just play nice there.