just set your realmlist.wtf back to the original address where you come from (us/eu) and then log in with any name/pass possible.
The game will update automatically.
That's how i've done it.
Are you playing wow in Chinese now on your mac?
i'm looking into it to playing it in Chinese on mine. But what version should i use? I'm now playing on a private server, 3.0.9 WOTLK.