If I understand you correctly you want to control Midi Designer parameters with your Drehbank and BCR2000?
Personally, I think that is possible. What you need to do is match the midi messages that you are sending.
So for example, if your BCR2000 knob sends a midi CC 55 Midi Designer you will need a knob that is set to CC 55. And you need to have a midi connection from the BCR2000 to Midi Designer.
But why would you want to control Midi Designer with an external controller?