From the schematic, I see that there is provision made for the selection of either Vpp or Vdd to be applied to the Reset pin, controlled by the USB to BDM processor. It is possible that you may not need to do anything except select the correct MCU type from within CW.
prometeus wrote:
... the 'S08 MCUs don't use a programming voltage of 12V, so the Reset pin of the BDM connector is just used for reseting the MCU? So maybe I can use a transistor or a Z-diode+resistor to take down the voltage to 5V during reseting while programming. What do you think?