As long as you only have a .htm file and not a second .html file it won't matter. It looks for an index page in a particular order. I'm not exactly sure what that order is, but there is no problem as long as you only have one index file with an extension that is recognized - htm, html, shtml, php, etc.
When you set up your connection in Dreamweaver
ftp host - ftp.domain.com
your login and password should match your ftp account info
And passive ftp should be checked.
I hope this helps. There are some tutorials for setting up Dreamweaver with LP servers at
http://www.lunarpages.com/tutorials/ check the ones for shared hosting, using Dreamweaver.