SOLVED:
The SST software is the solution.
I programmed macros - different keys with different time delays, so this works.
But there's much more to do:
Press and hold fire, then you follow your rocket flight for e.g. 3 secs, then e.g. 3 secs you see your target, then back to your cockpit view - only until you hold the fire button. If you leave the fire button, you have your "normal" view again.
This is my task this weekend...