uh...uh..I don't know..I've seen a very few Mojoworld pics with objects in them. A lot of it looks like Postwork..I'd check the Mojo forum, they're more likely to have an answer..
That being said, you can make an image in Mojoworld, then File|Import|Background picture into Poser, and do it that way..Dr. Geep has a good tutorial on that..a few posts down from here..

I wish I'd said that.. The Staircase Wit

anahl nathrak uth vas betude doth yel dyenvey..;)