Since it doesn't look like anyone's answered this, I'll take a shot. (Hi, this is Dawn, I used to be copcast and I still help out with things from time to time.)

I think people get the approximate rank they had in their previous homes. I imagine there would be some kind of probationary period, though.

The Copcast tends to be pretty flexible that way, but if you wanted to play out an interview or test with the copcast I'm sure someone would be willing!