I think your rget doesn't need a ParseSub parameter, that is an optional parameter to provide your own directory parse function.

As far as I can see, Net::FTP::Recursive provides no method to only get some files of a directory, it just slurps everything that is in and under the current directory.

If you don't mind getting everything from that directory instead of only the ones you want, you just call rget without parameter. Otherwise you either have to read the current directory yourself and change to the directories you want or use a different module