Hello,
I really don't know why you want to do this, but there is a free piece of software called
Mpeg Streamclip .
The main purpose of this program is to convert mpeg files into AVI or Quicktime or DV files and vice versa, BUT, it also converts raw DVD movies files (.vob) files into DV files.
So what you can try to do is to copy the DVD onto your hard drive using
MacTheRipper just incase there is copy protection, and then open the videoTS folder using Mpeg Streamclip, then export to DV.
The eventual DV file can then be transferred to your miniDV camcorder i think, using iMovie.
There may be a better idea, but 'tis the best i could come up with.