Thanks guys. The only reason I chose to use complex profile wall for the moldings in the first place is because I hate having to create extra objects/morphs for each wall. I'm aware of the "Moldings and Panels" tool in the ArchiCAD Accessories, but the problem with that are the poor intersections and lack of height adjustment.
I'm going to go with the Cut Plane option, it seems plausible in my situation. Again thanks a lot