Process Unicode-data from Oracle database

Hi,

I want to access with Visual basic 6 to data, which are present in a Oracle database in
the unicode format. Now I can connect to the database and I can process tables, which contain only ASCII data, without problems, but as soon as unicode comes into the play...?
And the StrConv function functions also not as intended. Oh, it can be that a table contains both AscII text and unicode-data (e.g. Russian o. asiatic characters). How I can differentiate between this.
Please help me, and write everything what you know about unicode and VB.

THANKS Sascha