I have finished an alike project----a 4-freedom arm, using joystick(made by 4 pots) to control it.
With all due respect, Stargazer, moving the end of a servo with four pots is not an "alike project". It's simply 4 knob programs in one and is simple in comparison to inverse kinematics in 3D and real time.
But it might be enough for the OP, who went silent after January 14th.
As a compromise though, I recently experimented a bit with using the potentiometer (knob) approach and using a push button on an interrupt to store the current settings of the pots into EEPROM as the servos move.That was a very ( very)basic way of programming the actuator path, by recording waypoints as it was driven by the pot (pot singular, for my testing.) Then I had another program that read the EEPROM values back and moved the actuator on its pre-programmed path. Timing is an issue.....