[texhax] greek letters in ghostscript

[I.Caretti]

dear texhax:

I have a problem with greek letters in *.eps format. When I export a graph 
from Origin in EPS fomat the greek letters disappear.
So, I cannot include EPS figures in LaTeX with greek letters. I tried with 
exporting the graphs as WMF and then converting with WMF2EPS, and it 
worked, but the graphs are very different in colour, size, contrast, 
transparency, etc. from the directly exported to EPS.
What can I do to solve this problem???? Do I Have to include symbol fonts 
or anything similar in Ghostscript?

Thanks in advance

I.Caretti