aspell.conf is not recognized under windows

Hey,

I want to use aspell C-Api in a program and managed to get it working
nicely, but
I need to provide the envvar LANG instead of being able to use a
aspell.conf in the home directory.
Also I tried to set the conf-dir via aspell_config_replace which
worked internally because a apsell_config_retrieve showed that what I
have set. But the aspell.conf in this directory was not recognized
too. also a .aspell.conf there did not work.

I tried it with aspell_config_clone, no success too.

btw. the new_aspell_speller is called afterwards of course, with the
cloned or changed config as parameter.

the error what i do get is 'No word lists can be found for the
language "en_US" '
en_US I think is the default if no envvar or aspell.conf respectively
.aspell.conf was found.

Any suggestions? 

Ciao Ephraim