[Fontconfig] Virtual font to access multiple characters

[rhino64 at postmail.ch]

Hi All,
      I would have some kind of virtual font to access multiple
glyphs located in differrent physical fonts. This is useful for instance
to have the roman glyphs in one fonts while the greek in an other
font.

I have googled and look (briefly) in the mailing list archive, but I have just found
some mentions that should be possible without some indications how to do it.

Any idea ?

thanks for your help,

regards

Alain