I used this schematic as my guide when I hooked up my driving lights...

I think the "any wire with power" wire is the wire you're looking for, if I understand your
question.
You could use the ACC wire behind the right side cover.
I didn't add an extra switch to my driving lights, and used the blue wire that goes to
the headlight for my "any" wire, and my driving lights only come on when I hit high beam.
-Mike "sorry if I misunderstood your question..."