compressed file extraction

I need to search a given directory to see if it contains any .pk3 files. pk3 is a compressed file format exactly the same as winzip creates. Then I need to open that compressed pk3 and search for any gif or jpg images in it. If I find any, I need to extract a copy of them and place it in another directory. I figured out how to search the directory for the pk3 file, but I am lost as how to work with compressed files.

This is what I suggest. Go to this website:

http://www.yoda.arachsys.com/csharp/faq/

There is a FAQ regarding unzipping and zipping files with .Net. There is a free open source class you can download called ShareZip, or something like that..there is a direct link to the source code. It also provides free C# code samples. I am certain this code can also be translated or migrated into VB.net quite easily.