Assuming your intent is to have a daughter board mount on a CPU board, I'm not sure you wouldn't be better to just make a breadboard part with the daughter board in place and not bother with trying to make it connect. I'd then have two blocks in schematic (one for the daughter board one for the cpu board) with preconnected wires between the two blocks. The plugable in version is a lot of work for not much gain (being able to plug in a wall wart in bb as in real life struck me as possibly useful though).
Peter
