using mouse as midi controller

Due to the rather keen price GPO can be picked up for right now, I'm really getting into it. However, my master keyboard is a weighted 88 note and does not have pitch/mod wheels.

I have a Kensington trackball that looks like something out of Star Trek and lights up blue every time you move the translucent crystal ball. It would make a fantastic prop for Dr. Who.

Tacky styling aside, it seems to me this would make a fantastic controller for GPO because you could assign two independent parameters such as pitch and volume to the two axes of the trackball.

However, I can't locate any software that performs this simple task, i.e allows a mouse/trackball to control pitch and modulation wheels on plugins within Sonar. By 'control' I don't mean by having to click on tiny replicas of mod wheels and pitch wheels; I mean that for some period of time controlled perhaps with a mouse click on and off, the mouse will directly control two MIDI controllers, one for each axis.

Any thoughts, folks. I've sure found some great software by asking here perviously over the years.