These would have to be two separate bookings, but you are able to have them "linked" by asking for the TCP details of the two bookings being linked.
If you are looking for the tickets to be on the same PNR, perhaps book one leg as cash, the other by points (provided the availability). You are able to do this quite easily (pending availability) on the QF site as it throws up the Classic awards with the Revenue fares.
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