lost code rover radio?

can anyone help me with a radio code for a R770 radio casette player in my Rover 45.I am aware that I can buy the code (lost after battery disconnection in the snowy weather)but this is probably costs more than the car is worth.I need to be back to 5 live! type no. 22DC594/60B
RG PART XQD101260
PRODUCT NO. 0600131143167. many thanks