[ODE] Joints where only 1 body is affected

[Wesley Smith]

I'm trying to figure out how to attach a joint betwen 2 objects and
only have it act on one of them.  Both objects can move in the
environment, so setting the body to 0 for one of th ebodies in
dJointAttach is not an option.  Is there a flag somewhere that says
only affect body 2?  I'm trying to simulate an object moving with a
rope attached to it where the rope is anchored to the moving body.
For this I need to attach a ball joint between the body and the first
link of the rope, but this causes the body to move as well.  Any
ideas?

thanks,
wes