I am looking to fly MEL-LHR-CDG.

My final destination is Paris.

Can I book this online any where or do I need to call the airline?

Secondly, if I decide to cancel are the miles refundable?

Do I need to use 2 lots of miles, firstly for the MEL-LHR and secondly for the LHR-CDG? I only say LHR as that is the best option to keep going on One World carriers.

Finally, I notice QF code share on AF SIN-CDG (it has a QF flight number), would I be able to get onto that using AA miles?