Assign Midi Control Surface BTN to VST Synth using ACT?

Hey fellow X3 enthusiests, I'd like to assign the preset up and down controlls on a VST to a midi controller button, do any of you have suggestions on how to do that?
 
As part of my workflow I like to cycle through synth sounds until I find the one that fits, doing so currently requires taking hand off keyboard, find mouse, hover up for the preset up/down control, then click.  I'd much rather press a button on my midi controller, that would be much more efficient.
 
The VST's have ACT mode, but I do not see away to configure the preset up and down, any tips are much appreciated.
 
Peace All,
 
Tom