[XeTeX] about the using \somefont/B or \somefont/I

[Dalyoung]

Hi all,

Many korean fonts have  "AppleGothic Regular"or "SD02 Medium" or 
"smMyungjoR W30" as  their normal font names and the naming scheme is 
little different.
Hence the command both "SD02/B" and "SD02 Medium/B" yielded errors as 
following:
	1. ! Font \newfont={SD02/B} not loadable: Metric (TFM) file or ATSUI 
font not found.
and the command " also yielded an error,
	2. Font \newfont={SD02 not loadable: Metric (TFM) file or ATSUI font 
not found.
<to be read again>
                    M
l.29 \font\newfont{SD02 M
                          edium/B}.

Because of this, I couldn't use a nice working "fontspec" for korean 
fonts. Now, I defeined a short macros to declare the korean fonts.
Is there a way to get rid of those errors by doing some modification?

Thank you for reading.

Dalyoung