... thats a first...
well, in that case, you just ADD the file realmlist.wtf to the chinese client.
and in it you write:
SET realmlist "<INSERT THE EU SERVER ADRESS HERE>"
and please don't forget to load World of Warcraft with the WoW.EXE, and not the launcher.
using the launcher will totallymess up your realmlist again and set it to china.
Come and join on Starcraft 2 as well =]