Well, i got the same idea. But nope. It dont work. Its not the same result, but both times the screen start on the left screen. With x = 0 the game window. And with x = 1920 on my mainscreen, but the left one is just black and not usable.
I tried it then with a resolution of 5920x1440. The alignment is then right, but the left screen still black.
Okay, my solution is now this:
Its not perfect, but i think i can live with that. 1. is my main game monitor, 2. the touchscreen and 3. the "browser" monitor.