Is it possible to make a ldraw model in Bricksmith be a sub model?

[Tommy Styrvoky]

I have been using Bricksmith on my mac for a while, and like the user interface, is it possible to add sub models in the program, like mlcad, as I know it can open up mpd files fine. I know that models can be inserted as a reference, but I don't know about a sub model. As I don't like having to reboot my computer to windows every time I want to work on a model with sub models for instructions.