Unzipping multiple ZIP files each into their own directory

I am trying to make a button to do several things:

a) select all .ZIP files in the directory
b) unzip each file into it's own directory names after the ZIP filename

I'm having No success at all - I've made other buttons successfully but this has me beat!

Any ideas?

Select PATTERN *.zip
Copy HERE EXTRACT=sub

...should do the trick.