A lot of things can be found using Regular Expressions, but does it make sense? I would suggest you use some HTML parser. It would be very simple for documents which are well-formed as XML, because XML parsers are readily available in .NET. It's so bad that unfortunately, many HTML documents are not well-formed. In this case, you need some other approach. Look at this one:
http://www.majestic12.co.uk/projects/html_parser.php[
^].
Good luck,
—SA