First, a correction: The correct address through the hosting server is myblogname.hostingcompanyname.com, instead of http://www.hostingcompanyname.com/myblogname as I wrote on the first post.
1. WordPress is installed at the FTP root directory of my hosting server, so I can access it by typing myblogname.hostingcompanyname.com.
2. The domain name http://www.myblogname.com is set up to redirect to myblogname.hostingcompanyname.com.
3. Yes, that’s the way I access it. Forget the http://www.hostingcompanyname.com/myblogname.