Can I use my aunt's address in California and im in adifferent country? Afterwards she will be the one to send me the check I will withdraw the refund outside USA. Will this be possible?

Yes, that should be fine.  Please note that you will probably receive a letter from California tax department since you will have a CA address on your federal return, they will want to know why you did not file a CA return.  Just respond back that you were only using your aunt's address for convenience.