So, theoretically if on the following itin:
CAI-LHR(trf)-NRT-HKG-AKL-MEL-AKL-SCL-LIM-SCL-GRU-LHR-CAI
could I tack on LHR-THR-LHR, stopping over in London a 2nd time between returning from GRU and going on to CAI (as outlined above).
Sorry if this isn't coming out as terribly comprehensible English!!