[Trump]

At the moment, i can't think of any way to do this specifically, but something that we've done in the past is to send autonomous signals based on time. For example, raise shoulder at .6 speed for 1 sec, then raise elbow at .3 speed for 2 seconds. With some tweaking, you should be able to get a pretty smooth motion, however position won't be exact.

If you have some sort of positional feedback on the arm (potentiometers, encoders...) you could find what the positions of the arm are after the driver gets it to a spot that they want it. Then set the arm to move to those predefined positions. In this case, the arm will go to the same spot every time.