Reply to Traktor midi mapping - using a fader to turn on a button

Hi Folks, first post here and this one relates to a TCI file for the VCI 100 by DJTT.

I have a Pioneer Wego and running Traktor Pro 2.6, but I am trying to code/midi map the FX combo function seen on the VCI 100 mapping by DJTT, seen on this link:



I have pretty much done it, except for the last component, where the fader used to control the Button 2 and Knob 2 (the volume fader on the controller) finally turns on the Button 3 when in the bottom position. I have tried a few things but can't get it, including the 'invert' function and using the volume fader control as it's own modifier. Not having much luck. If anyone has any helpful hints would be greatly appreciated.