Dear Mojca and Wolfgang, Thank you for the comments on lang-kor.tex.
I didn't test, but I would say: forget the dirty hacks and simply write \setuplabeltext [\s!ko] [\v!figure=??] It might not work in pdfTeX, but for XeTeX and LuaTeX it should do the job. Once you do those changes, feel free to ask again if you have problems (and don't forget to ask Hans to include the translations).
I modify the files following your advice. It removes the middle variable "\koencoding" and make the file simpler. And I don't need to use "\koencoding{\enableencoding[cjk- uni]}". It worked fine, also. But I'd like to use \setuphead for chapter, section, etc because our writing style of head is different from that of english. I uploaded it in KTUG board to be checked by them, since it may be need more corrections. Thank you again. By the way, do you completely resolve the "lmtypewriter10-regular" problem? which was discussed before in the list? Yesterday, after I reinstalled TeXlive and updated ConTeXt, I got "kpathsea: Running mktextfm lmtypewriter10-regular " message. As a temporary method, I renamed mktextfm. I confirmed that such font file is in texlive opentype font folder and lm*.map files in map/dvipdfm folder. Is there anything that I have to do more? I couldn't see the solution in the list. Thank you for reading. Best regards, Dalyoung