You could do it with morphs or you could tie multiple children to the cape. I'm assuming you want the main bone of the cape to be the chest or neck - I'd actually not tie that bone to any geometry by the way, just use it as a parent.  Then what you'd do is create three children from that bone and then children for each of those. That way, you simple select the "body part" to get the affect you want. It should work...in theory...I've not tried it but planned to for another project.  You may still want to tie morphs to certain bones to achieve different affects while bending but that's up to you. You  can use EasyPose Underground for that or any other program that lets you write ERC stuff and tie it to bone movement.

Or you can do what you're thinking, which would be more controlled but may be somewhat limited.  I'm not super rig expert guy - I'm a modeler - so take my thoughts with a grain of salt.  You should ask this in the Poser Technical Forum or the Character Creator forum, where it's more appropriate and may get you better answers..   I'm not a mod anymore, so I can't move the thread, it's just a suggestion. No harm in asking in both places I think.