Movers in Hamburg, Germany

I know that White Light in London has a system that uses a laptop to operate a moving-light-followspot. There's a camera at the instrument, and you use the mouse on the computer to follow the performer's feet. White Light may not be useful if you're not in the U.K., but it sounds like a simple enough system to mock up, at least roughly.

What about a trackball?

What kind of console are you using? If it's an EOS family you may be able to devise a solution for translating HID input to OSC that can be sent to the console.

I have done it with the MA2's trackball. Borderline impossible to do it perfectly, but good enough at least

If you are interested I have experience working with a program called Light Factory which is compatible with the USB DMX box you seem to be using. Last I used it, I just plugged in a USB joystick I had (Logitech attack 3), selected the fixture. And it just moved with the joystick no problem no setup.

Not sure if this would work for you. But I work with the Leapfrog 96 and I can control it through my pc. So I used a Joystick on the pc and that controlled the moving head.