Neither of my cordless drills have a collar, almost all mains ones did. If you do manage to mount it, a spring clamp or even a peg might hold the trigger in, you need something a bit "precarious" so you can knock it off in an instant, string or cable ties would make it hard to turn off quickly and there is no plug to pull out. The mains ones had a trigger with a button to hold it in, the button was designed to let go with the lightest touch on the trigger. If you are working where there is electricity, why not get a pre owned mains drill, I keep my old Bosch for just this sort of thing.