CAN Bus Control Unit: AHF-TDI Conversion?

I plan to replace the engine control unit (ECU) of my 110hp AHF TDI with one that supports CAN-BUS. Since my Golf is a 1998 model, it doesn't have CAN-BUS, but I want to install a new instrument cluster that relies on CAN-BUS.
'Could someone perhaps tell me if it's possible to simply replace the control unit with a newer one, and what problems or work should I expect?'