[Wild.Bill.Kelso]

Try creating a Hold type button. Check the 'No Reset' checkbox so it doesn't turn off until you touch it again.

Use a Macro with a Keydown in the _select part and a Keyup in the _deselect part like this:

macro_select = predef:B, KEYDOWN
macro_deselect = predef:B, KEYUP

I use this to hold the B key down for Brakes in IL2/Pacific Fighters.

You could also try making it a Touch type button if you only want it down 'while' you are actually touching it.

WBK