You'll need the Live.api.explorer to see the different paths that access control_surfaces 0
Can you not achieve what you want by mapping the VST to a rack and then controlling the parameters with the device control section of the APC?
You'll understand that there is no APC40 editor! I'm sure one day someone will make one but for now most of the control_surfaces part of Max4Live is undocumented so you'll have to bear with it and use trial and error!
ps whilst you're waiting i'd do all the tutorials, you wouldn't believe how many circles i went in when i could have known the solution by doing the tutorials first....
let me just add that the idea of putting a vst/au in a rack is a really really good idea i never thought of to get the knob assignments i would expect for an apc40! i might even do this for analog and operator to get the knobs in the order i want/expect!!!!!!