locale spec for greek fonts?

[Rich Winkel]

Hi, I'm trying to use greek fonts in x11/kde in 4.8-release. 
I'm currently using

MM_CHARSET=ISO-8859-7; export MM_CHARSET
LANG=el_GR; export LANG
LC_ALL=el_GR; export LC_ALL

But I keep getting the error:
Warning: locale not supported by C library, locale unchanged

Can someone point me in the right direction?

Thanks! (in hopeful anticipation :)
Rich