What is the requirement for a font to show up in the Complex Script Font
combo box in Word 2003?

We have a Unicode font that supports only the Devanagari range of Unicode
and we're trying to make it the default font for complex script text, but it
doesn't show up in the list. I suspect it is some information that is
lacking in the font file. Could someone let me know what that might be so I
can let the vendor know how to fix it?

Also, why is it that sometimes I can't change the font of a run of text with
the font combo box on the main formatting toolbar? The font has a glyph for
every character in the run of text (Devanagari range of Unicode), but for
some reason, Word doesn't think it's capable (due to 'language
detection'???) and therefore won't allow the change. Incidentally, I've
turned off the "Automatically detect language" for everything I can find and
it still doesn't work...

Is there a way to turn it off for real?

Thanks,
Bob