Seeing that it's CX. NO.

They will say that you've done your asia already, and that you cannot backtrack.

Again each oneworld partner, or even each person reading the rules will interpret it their own way. I've dealth with CX, QF, BA, AA and once with CP. Each airline interpretted a certain routing their own way. In the end CP gave the most logical solution and I ticketed through them. Pity.