Exchanges in medicine are very few and far between. You might be able to go but the chances of transferring credit back to your Oz degree are close to 0 unless there is a specific agreement set up between the med school and an equivalent in Sth Korea.
Best to ask your faculty directly because any exchange in medicine will require them to approve it and it's best to do that right up front before even bothering with the administrative formalities of exchange with the international office.
merillem is right. There is 0 chance of you going on an exchange while you are studying medicine. You can, however, enroll in combined Medicine and Arts and go on an exchange through the Arts program. You will get credits toward your Arts program.