Walk behind Troubles, Image links included....(Solved)

[J.E.S.]

Is there a way I can import a new walk-behind mask depending on my characters actions or location? I have 2 images as an example of what I want to do. The image with the green cursor next to the sofa is the effect I want and the image with the red cursor is what I'm struggling with. Changing the baseline does not work because of my room being in isometric view and that particular object.

http://s96.photobucket.com/albums/l183/virgoman25/?action=view&current=Image6.png (What I want)
http://s96.photobucket.com/albums/l183/virgoman25/?action=view&current=Image5.png (What I don't want)

[J.E.S.]

After a little more research I found something called,"SetWalkBehindBase". Which all I needed to do was create 2 separate walk-behind areas on my sofa. The piece that stuck out was coded to be drawn behind my character when he sat on the sofa.