Flipping the fader on an 'Instrument' track

Hi-

Can you flip the fader function on an Instrument track?

The Big Fader controls the Audio return(per it's aux function), and the small fader on top controls MIDI Volume per the Midi portion of the channel.

What i am trying to do is Use a control surface to control the midi volume on the Instrument Track.

Any thoughts or ideas how to achieve that?

The simplest would have been to Flip that fader so the bottom portion of the Track behaves like the Midi portion and the above portion behaves as the Aux function of the Track.

Thanks for your advice.