Thanks for the link! I had a quick look just now, pretty much like what I figured. But the details can be hairy, so it's nice to have the document to go by.

I know how to set up weigh-mapping via the joint editor, and I agree that starting with spheres and then use that function that bakes all existing deformers into a weight-map is the best way.

My question was specifically about copying an existing weight map to a different channel, say from x-rotate to y-rotate. Come to think of it, I'm pretty sure the weight-map editor actually has copy/paste functionality (it does in P12, anyway), which I've used before. So I could have just asked my past self. :-)

-- I'm not mad at you, just Westphalian.