Hey Robot,
All you need to do is choose any control change you want.
Assign an "Event Type" of "MIDI CC" to the pitch argument of your Wiimote /wii/1/accel/pry message, as a value you can choose for example '0'. This will send pitch values on control change 0.
Now, you have to tell Live that you want to control the fader with CC 0.
To go in MIDI Learn mode, press Command-M. With your mouse, select the fader you want to control.
Since the Wiimote is already sending messages on control change 0, as soon as you select the fader, it will be mapped to this control change. This is not a problem, just something you have to be aware of.
Now, the fader is controlled by the Wiimote's pitch. To make it more usable, you can adjust the range either in Live or in OSCulator, in the Scalings Page.
Best,
Cam