Hi grid, I'm not sure you can do what you want using a morph target. The movable part's shape will get distorted when you try to apply the morph. I believe this needs to be done as a figure with the movable piece(s) done as separate body parts with "bend"ing turned OFF. (as shown above) cheers, dr geep ;=]
Remember ... "With Poser, all things are possible, and poseable!"
cheers,
dr geep ... :o]
edited 10/5/2019