Spela
multi touch is a lot more effort than single touch.
in my experience, the best way to handle multi touch is to create a sprite called touchpoint and use that to track each touch. You create one on every touch start, update where it is every tick, and destroy it when that touch ends. that way you know exactly where the touch started, how long it has been in touch, and can control what it is allowed to do, what it should ignore, etc...
I made a quick sample, where I copied parts of my standard multi touch routines, so it is doing slightly more than what you asked for, but might be useful to see how I like to do it.
https://www.rieperts.com/games/forum/multitouch.capx