In your 120kt RA-Aus aircraft?
To be honest, I don't know what the training for a CPL involves, other than navexs to a higher standard, and general flying to a higher standard.
Also, the CPL requires 140 hours flight time, including 70 PIC, in a VH registered aircraft. So I guess you could get a PPL, get those hours, get the training in your high speed RAAus machine, then do your flight test in the same aircraft registered VH. Seems pretty complex.