Since you mentioned ANA/UA, what about an itin on UA/NZ? You could do SYD-AKL-HNL on NZ on the return, fly over to SYD on UA (or NZ) and connect to MEL on NZ(codeshare on AN).
The NZ service AKL-HNL may even be a UA codeshare, and as UA flies MEL-AKL, you could do something like: LAX-SYD-MEL(UA c/s on AN)-AKL-HNL-LAX.
Justa thought.
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RichardMEL, UA 1K
A Star Alliance Member.