Is there a way I can play my Werkstatt via CV?

The Werkstatt can certainly be played with external CV gear: patch the pitch CV into the Werkstatt’s VCO EXP FM In and switch the Werkstatt’s gate On. You may need to calibrate the Werkstatt’s VCO input, this can be done via trimmer VR5 (VCO EXP In) on the circuit board.