If you don't mind flying a "dry" airline, Egypt Air flies to Guangzhou from Cairo. I flew them from/to ATH last March for about 1500 Euro in business. And if you fly A3 LON-ATH-CAI to get to them, here are, as a bonus, your 4 A3 flights!

As far as earning miles are concerned you will never, ever, have enough miles for a LON to ATH award flight in F; to my knowledge there is not a single *A airline offering that connection in F.