I don't have personal experience with this but it appears that you need wide character filenames (normal encoding doesn't have the "pound sterling" symbol. You might find this helpful..
http://aspn.activestate.com/ASPN/Mail/Message/perl-win32-users/3171931
although it sounds like you are going to have do some work. You might want to also look into Perl 5.10 to see if somehow this got better. Sorry I can't help more. Good luck!