Good use of the wshell object. This is cleaner than the "shell" command used in VB which normally runs asynchronously. I see in a couple places you're declaring more than one instance of the file system object...why? Also, I think you're using the DONE file as an indicator that the copy of the zip file to the folder is complete?
Note to Readers: Pkzipc is the command line version of PKzip and is not installed on your server by default!
Andy