Moment Force


I have a problem with moment application. Due the fact that force moment is a force couple, it is logical to assume that it is enough to apply two forces to set rotation of the geometry.
Suppose there is an area of geometry (A), Figure 1. The rotational center (O) and the point of application of the force F1 (OF1) I can specify by the node number. The force vector F1 as a function of two coefficients (CoefficientFunction ((x, y))).
The question is how to deal with the OF2 point, which is outside the area (A)? Should I create a node in the computational mesh at the point OF2 and explicitly apply the force F2 to it?
Thank you in advance!
Yours sincerely, Aleksandr.