It depends on what you are trying to ultimately accomplish, but in a short answer kind of way...yes.
Let's say you have a head with 2 ears, but the whole head is only grouped as "head", ie; the ears are not individually grouped. You can add 2 bones to the head, move those into position for the ears, create some Sphere Zones and have them influence each ear with dials.

However, because the ears are not grouped if/when you pressed the joint editors ZeroFigure button the ear dials would not zero out, you would have to do those by hand.
Hope this helps!

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