A few notes:
1) There is no point in adding :80. People type
http://yahoo.com, not
http://yahoo.com:80
2) There is no point in including the IP of the domain, again people access the web site using the domain name.
If by "p.s Im at nt host at prohosters " you mean that you are on a Windows NT server running Internet Information Server, then this thread will not help you, it does not support .htaccess.