I think a lot of the code from the Sun Tracker program could be reused to do what you want. More would have to be added though. For calculating the position of the stars in particular. It's totally doable, but it would probably be a lot of work. I've surprised that there isn't already something out there.
I have an interest in astronomy, but I don't actually own a telescope. Otherwise I might have tried doing this myself.
It's on my list of things I want to try. Of course, its a long list, so it could be awhile.