6DOF Positioning of Objects

Hello,

and thanks for answering my last stupid question, even if 
it turned out that it was a bug in my application (when 
rotating > pi).
However, I just have another problem: I want to use a 
tracker in combination with a cyberglove. Thus, the 
position and orientation of a virtual hand should be 
controlled by the tracker, and the movement of the fingers 
by the glove. When I directly set the position and 
orientation of the palm from the tracker input, the joints 
of the fingers that are connected to the palm, go crazy. 
So I tried to use joints instead of setting the 
orientation of the palm directly. Therefore I used 3 
slider joints to control the position and 3 hinge joints 
for the orientation. But using euler-angles for the hinge 
joints results in singularities. So it would be better to 
use quaternions for the orientation.
So my question: Is it possible to control the orientation 
of a ball joint or a motor via quaternions? I couldn`t 
find something like that in the documentation.
Or am I completley wrong and there exists an far easier 
way for a 6 DOF control for a moving hand?

Thanks in advance,
Rene