You can't do that. When dealing with file uploads on the server side, the files *have all ready been uploaded* to a temporary location, you cannot reach *back* to the client from the server.
What you could do is upload a file containing a list of files and then return a form that contains the files to be uploaded pre-filled - just awaiting the user to hit submit (or if you're really evil - add a javascript handler to autosubmit - hmmm can that be done?). You may also want to use
CGI's upload function (or at least read the *CREATING A FILE UPLOAD FIELD* section of
CGI).
Update: Doh! The AM below is correct. Most browsers will not pre-fill a file input field.