Just a remark: for cjk one can best use the mkiv feature to combine fonts; there are probably some examples of korean fonts mixed with e.g. palatino or times in the email archive.

Here is a sample typescript file for mixed Korean and English fonts suggested by Hans. Using this file, I can use Korean font for Korean and Palatino for English. It works well. You can modify this file for your purpose. Good luck! Best regards, Dalyoung