I played dial-a-CSR and tried to get eastward routings to OZ on KL, AF, VS, and even EK. I even tried to use CO to go BF to TLV and then buy a ticket with cash onwards. Nada.

Every CO Elite Desk CSR said that I "had" to route westward to OZ. Based on that, I did KE, which was pretty easy to get. You have to be creative and remember that they serve many North American cities, including JFK, YYZ, ORD, and LAX. Since CO flies to each of those, you can build a pretty nice trip.

All that said JFK-ICN-SYD is way, waay, waaay, out of the way. Yes, you might be in C/J, but when you do the math, you might just prefer to fly CO to LAX, SFO, or HNL and fly QF in Y from there.

P.S. Don't forget about EVA airlines. Again, TPE is out of the way, but they have a lot of availability to Asia.