Different language client, same account?

Is there a way for me to log on to wow using a different language client but my same account? I mean, I have a few characters on a few different US servers, even though I live in Korea. Is there a way to log onto the US servers using my normal account via the korean client? Or is there another way to work around the issue? Would I have to get a second "korean" account? If so, how can I do that, as one of the "required bits of information" to get a korean account is your "Citizen Registration Number" (basically like a SSN, but in korea) which I don't have since I'm a US citizen.

Bottom line, I have a US account. I want to be able to play (not permanetly or always, but sometimes) using a korean language client. Possible? How?