Why would you do this? The only obvious reason to fly Qantas is your lounge access due to elite status.

There is a Virgin/Etihad fare in August of $3009 which is Premium Economy to Abu Dhabi followed by Economy onwards.

China Airlines has real Business Class for $4299 all inclusive in August, while China Southern and Eva Air are $500 dearer.

Or for $4599 you can get a Finnair mixed class fare, which is Economy on Qantas to Hong Kong, Singapore or Bangkok followed by Business Class on Finnair to your destination.

Qantas seems a fairly poor choice for your purposes.