How to set raw header using winHttp for user name?

I used to access my own small server using Qt, and I could set my raw header using Qt like this:

        QString concatenated = "admin:admin";
        newRequest.setRawHeader("Authorization", concatenated.toLocal8Bit());

But how could I do the same thing using winHttp? How could I add the username password as admin:admin in my winHttp header?

via Chebli Mohamed