Here you find a full tutorial in the Wiki to retrofit the DAB-Module: https://mk4-wiki.denkdose.de/artikel/dab/dab_nachruesten/start
No configuration is needed for DAB. If your MCA has the right firmware (SP2015 installed) and the DAB-module is connected to the MM-CAN, they will find eachother and the "DAB" button shows up in the MCA screen.
You could change the CCC for DAB but this was more for the IPC (Convers+). Unfortunately you cannot get it into your preFL Convers+ as for DAB-Function at least Firmware 1412 is needed, which can't be installed on preFL IPC, only on FL IPC. But FL IPC can only be fitted to preFL with a patched (Russian) Firmware which is not able to handle DAB. So no way to get DAB controls into the IPC.
The key to get DAB to work is that CAN-Pins of the module (see DAB-harness in the wiki article) are connected to the satnav Quadlock. This is pin 10 (MM-CAN HI) of DAB plug to Pin A-9 of Satnav Quadlock (blue/grey wire) and pin 5 (MM-CAN LO) of DAB to Pin A-10 of Quadlock (violet/grey wire). If the module has 12V power, that's enough in the first to get it show up. If it is not showing up, try to swap the CAN pins on the module plug in case you mixed it up.
If the module does not show up, it might(!) be damaged. Put an multimeter in mA range in series with the 12V line and measure the power draw. It should be around 60-80 mA in the first 2 minutes.
If it helps, i could check your module, but you need to ship it to me somehow.