Hi Nico
It should be possible (although it will require a fairly complex QPAC)
It should be possible to create an "AttachDocumentToTask" QPAC that would basically do exactly the same as what the User QPAC does, but skip the bit in the middle where the User actually gets involved.
So it would assign a task to a user, set up the document for that user to complete, and then automatically complete the step.
This would mean that the document should then appear in the "Participated" folder for that user in Form Manager, exactly as if the user had completed the form manually.
It may also be possible to set this up using the Archive folder, as you suggest. However, this would take some additional research, as I don't know how to access that folder.
Note that this solution would only make the form accessible to the specific user that you "assigned" to it - is that your intention, or do you want to make the form more generally accessible?
Howard
http://www.avoka.com