Double posting is wrong. :3
So, you need to connect to their servers once with a korean IP Address to unlock your account, or something. ._. /Kowiz
Get a korean proxy and use it to log in. After that, you can just switch back to your old computer settings. :3
You should know how to proxy if you're migrating as a group, ask one of the people who plan to migrate.
I'm on GW2! Except I don't know my own Account name!