My memory on this is a little vague but I'm almost certain the answer is no and the AA flight numbers can only be booked with continuing onward travel without a stopover in either NRT or HKG.
I took a flight the other way from HKG-xNRT-DFW on a LONE4 and had a very long and painful process just getting the AA agent to be able to book the AA flight number on the CX metal, Expertflyer was showing it and the agent could see the flight but not book it for some reason. They were eventually able to do it but not without a lot of messing around and as stated above I'm almost certain the codeshares can only be used on through travel not stopovers.
Others may have a different experience?