Hi Florian,
We definitely need a new node that can rotate around the given origin. The current rotation nodes are always rotate around the origin so you can do the rotation first, and then move the object to the desired position.
If you want to modifiy the rotation origin of the object you can move it so the desired rotation origin will be in the global origin. Now you can do the rotation and can move it back to it's original position.
I've created a new issue to make the extended rotation node available.