Hey @Jim_Arabajoglou!
Do you have access to the original model? If so, since you are wanting something very specific, it may be better to split the model in three in a model editor (blender, maya, etc) and bring them back into the engine to make a modular mesh. That will give you the most finite control.
Otherwise, check out this thread post that may have the answer you need:
I hope the above contains the solution you need!