How are you interfacing it? Parallel or serial? If it's parallel, you could probably find a cheap, 8 bit A/D converter and hook that up to an analog pot.
The potentiometers you mention probably aren't potentiometers at all, but, um, dial thingies. They won't give you a value between min and max, but will only tell you when it goes up or down. Turn it left and it sends one signal, the other way a different signal. They work like the volume knobs on most modern stereos. This may work for you, though.