Creating Value Parameters when an effect is Pickwhipped to the parameters on a adjustment layer with sound keys

here's my situation:
i have placed sound keys on an adjustment layer
on another adjustment layer [adjustment layer 2 in this case] i have a photograph underneath it
on adjustment layer 2 i have placed the mirror effect, what i'd like to do is create parameters so that the reflection angle is either 270 or 90, while pickwhipped to the Output 3 layer of the adjustment layer that has sound keys.

so i'm just curious regarding how to establish parameters in this case of only two values yet those two values are triggered via the keyframes from the sound keys imbued adjustment layer.

hopefully that makes sense,
thanks in advance

Rich


adjustment layer 2
thisComp.layer("Adjustment Layer 1").effect("Sound Keys")("Output 3")