Thank you, Peter! I also found the mathpages.com page you mentioned in that thread. I would mark you answer as the correct answer if I could.See the papers linked to in the post I just referenced. I won't say the answers given there are "simple", but they at least give some good info on how a scenario like the one you are thinking of can be formulated in GR.
I will return after I have enough training in understanding the two papers.