How to disable proximity sensor

I dropped my Motorola Charm (Android 2.1) and the proximity sensor doesn't work which is annoying, it makes the the touchscreen disabled when I dial anything (super annoying). I would rather like to disable the proximity sensor, so it will never disable the touch screen. Does anybody know how I can do so? In case of absence of any ready made solutions, I am even willing to write my own app for that (there are programs that do that but for Android 2.2).