code radio (delphi swing) skoda : i need 4 digits number

I need a compact Delphi routine that takes the serial information from a Skoda Swing radio and returns the correct unlock code, then simply presents that code on-screen. The focus is solely on the Swing variant (not Bolero or Columbus), so feel free to streamline the logic for that single model... (Budget: €8 - €30 EUR, Jobs: C++ Programming, Debugging, Delphi, Programming, Software Architecture, Software Development, Software Engineering, x86/x64 Assembler)