You could program in 'C' using a compiler such as Keil C51 that provides floating point libraries.

Do you need to think of the position of the wheel in degrees? If you are using the position of the wheel for further calculation then you could just accept that the position from one end of travel to the other is represented by 0-FFF and adjust your calculation accordingly. It is (probably) possible to do whatever you want without floating point arithmetic - try searching for "fixed point arithmetic".