Yes, you can set up and Expression quite easily that will link the Motion Tracking Position (or Anchor Point) property to the Stereo Mixer effect's Left Pan and Right Pan properties. Use the Pickwhip to link the properties together. Then, if you need to adjust the range used you can use the Linear expression to do so.
Here's a tutorial that shows how to use the Linear Expression. Although this one links Time Remapping to the Audio Levels property, it's the same process, just substitute the different properties.
Angie's right about the expressions, but I have to tell you: audio isn't exactly AE's strong suit.
I may be old-fashioned, but I'd prefer to do the work in in an audio application or even a video editing application. They also would have the virture of seeing and hearing the result of your work in real time.
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