I'm not sure whether it is possible to use Firewire (IEEE 1394) to transfer video from PC to a mini DV cam. But you can use analog connections like S-Video (separate audio cable needed), RCA cable (separate audio cable may be needed) to connect to your camera. However I don't see any sense getting video recompressed for DVD (or was it just a raw stream?) and use analog connection to record it with your mini DV cam.

Why do you want to do that???