Obtaining raw device data in Win 98

I am trying to obtain the raw input from my mouse. To give background, I am part of a group building a robot and we are considering using the insides of a mouse to encode the change in the robot's position. I therefore wish to obtain the raw data input from the mouse (the x and y movement). I have looked through MSDN and have found all the stuff on WM_INPUT, RegisterRawInputDevices(), GetRawInputData() etc etc. But for every one it says at the bottom, minimum operating systems: Included in Windows XP. I assume this means that these functions are only available if you are running XP (which I am not) but surely it is possible to perform the same operations in win 98? Can anyone give me any pointers?