There is a feature in Vue allow an object to only cast a shadow, but I don't think that's what you're after. When you select an object, under the material preview you will see a number of small icons. The one with the ball and shadow under it allows an object to only cast a shadow. The shadow catcher feature in Poser works differently though, but perhaps this can be a little help as well.

Artwork and 3DToons items, create the perfect place for you toon and other figures!

http://www.renderosity.com/mod/bcs/index.php?vendor=23722

Due to the childish TOS changes, I'm not allowed to link to my other products outside of Rendo anymore :(

Food for thought.....
https://www.youtube.com/watch?v=pYZw0dfLmLk