as I got no answer to my last message about selecting single monitor within multi-monitor-environment, I found another possible solution ti fix this problem: The sharearea command line argument.
But unfortunately I arranged my monitors not in the normal way, but switched second and third one to the left. So this order results: 3 - 2 - 1 (from left to rigth).
No when I want to narrow down the server view to monitor 2+3 using the sharearea command line option, I theoretically would use it in this manner: 2560x1024-2560+0.
But the negativ x-value is not recognized by the system. Is there a way to set the share area to a negativ value? This option must be supported by thigthVNC, because I can pull the sharearea on the window manually to the rigth position using the mouse.