Night-Rida

Been searching everywhere can't find how to do this on my 2007 cls550. My defrost and recirc buttons are on the same rocker switch. Impossible to push both buttons down for five seconds at the same time. I also dont have a rest button like older mercs. My passenger side windshield defroster vent always blows cold at night and case heavy fogging. I figured out today if I turn auto ac off and turn that side on manual Ac to that defroster vent it actually stops. Which is good, but that means rotary vent select knob is off. I believe if I can do a calibration or reset it my correct problem. Any help is appreciated.