Thank you so much,
belive me, I was looking for it, but I was looking the wrong way:
I was searching for "rotate around selection". I am sorry for that,
but i handle 3 applications at the moment (Blender, CINEMA 4D and Moi)
and that leads sometimes to confusion like that.
Again sorry, and a big thank you for taking the time and helping me out!
Best regards
Heiner