This reminds me of Larry Wall's rename script, which at least on Debian systems comes with the default Perl install, at /usr/bin/prename. As far as I can tell, that's been extended upon and turned into File::Rename. Perhaps that could serve as some inspiration?

As for what appears to be the followup question here, I think it would probably indeed be best if you could post this in a new thread, along with code that demonstrates the problem (How do I post a question effectively?).