Hi Zigmund!
First, You should simulate cloth using constraint cloth without pin to target constraint , and then, you may see some part of cloth should be more free to flow in air, in that case you should get simulated output cloth from previous level as a input for new simulation using pin to target constraint and pin painted points from this cloth to corresponding points from last simulation,
Usually in "pin to target constraint " simulation we do pin points to corresponding points at simulated cloth not a fixed and unmoving cloth