Use of greek font for lyrics

Maybe it's not an issue, however, I couldn't find any solution to it via the search possibilities:
I have German Windows 2003 Server on my computer for several reasons which do not need to be explained here and am trying to enter a Greek song with (logically) Greek lyriks.
When I try to switch from the German to the Greek keyboard (left shift +left alt), nothing happens.
When switching via the "switch" in the task bar, nothing will happen if I try and type text.

Is that a bug or a feature?

Many thanks in advance

Angelo