I know this doesnt answer your question, but if you are rebuilding from scratch, why not use 1.8? This version has that same functionality (and more) in it's Advanced Upload Assignment type.
Thank you for your reply. We have actually upgraded to 1.8 from 1.6 and will be using the new Advanced Upload Assignment tyype. Our problem is we have a year's assignments and responses submitted while using 1.6 which we can't get at. Is there any way of tweaking 1.8 so we can get at these via the new Advanced Upload Assignment?