Kind of. You can enter an Aust credit card even if select country as US (+ caribbean etc). You will need to enter a US zip code and state (zip code to be consistent with state), other address lines should be your real address per credit card.
As long as amount of ticket isnt too high it will go through automatically. Some have referred to USD1000 being okay - the exact amount at which AA applies a full credit check (and thus fails to ticket automatically) is not known. If you don't get an email confirming ticketing within a day, you can check on the AA website the status. The wording changes when it is confirmed. I'm too lazy to look up what the wording is right now, a search on AFF or perhaps one of the AA gurus will soon reveal it.
Note the automatic ticketing normally is very quick but sometimes might take a day. If it takes longer then most likely it will not complete.
If it doesn't complete then you have a few days to contact an AA ticket office to provide the necessary credit card info for them to complete the ticketing.