You could try to:
Open the map containing your files,
get the extention using a regexp
search cpan for a zip-module like Archive::Zip

He, do you expect us to write it for you, or are you willing to read a book, tutorials and Q&A's on this site?

But anyway, i'd start by thinking about a good design etc., disign the tests needed, put it on paper, and start coding when finished.