I can't offer any practical help except to say that looking at the pin table file on the main community site may help. Also, you may want to check back issues of CineFX for an article about The Time Machine where they did exactly what you are trying to accomplish in Houdini, maybe there is something on the DVD as well. It might offer some insight. Lastly, check out
www.oddforce.net. It's run and frequented by people from major effects houses. If you drop a note in the forum I'm sure they will give you a hand.