Regex: Filter out -only- the root domain name

I have to enter my root domain name in an exclude path for a .NET module.

The Regular Expression required to indicate that ONLY the root domain name should be excluded, like:

www.domain.com
or
http://www.domain.com

but it should not exclude URL's that have extra items in the URL, such as:

www.domain.com/folder/mypage.htm

I tried:
(?!\bwww.domain.com\b)

but this seems to also include any sub-pages as well...

Solution found:

(domain\.com$)