Barcode:  Under the Figure option in the menu bar you can Set Figure Parent.

What Hioushi is saying is impossible is exactly what I'm trying to do:  save a figure in the same was as a smartprop.

I have a train car with 8 compartments, high or low res; I want to give folks the option of loading only the high-res ones they need and the rest low.  I suppose I can make the default load with all low-res compartments, and a user can delete one and add the high-res there, then parent it themselves.  I am trying to make it simple for novice users.

Does anyone know of a hack for this?