Set Reaction to output of chosen Return

Hello,

I am trying to create a reaction that:
1. I select Return A in Ableton.
2. I turn knob 1 on my control device.
3. Knob 1 changes the send amount/volume of Track 1 to Return A.
4. I select Return B in Ableton.
5. I turn knob 1 on my control device.
6. Knob 1 changes the send amount/volume of Track 1 to Return B.
7. I then turn knob 2.
8. Knob 2 changes the amount/volume of Track 2 to Return B.
…and so on and so forth.

Basically if a Return is selected have a knob control the amount of that selected send on a track that knob is’ hardwired’ to.

Thanks,
c3r1c3