> Yes.  Obviously, we did not know that these files were being sent to us
> Unicode.  But, by the nature of your response, I can see that we need
> to go to the third party and ask them to send them in a different
> format.

no I don’t mean that.
If you created them, then you can choose to create them in a way which makes
it easiest for you to handle them.
If they are supplied then you need to handle them in a professional way and
not ask for them to be altered (IMHO).

So you will need 2 columns, one for these unicode documents, and another for
plain text. Don’t mix them. Each column is declared with its own character
set.
Then you should be able to search both with
WHERE FIELD1 CONTAINING 'my search string' OR FIELD2 CONTAINING 'my search
string';

Alan