You can use XPath in C#

I have not migrated to .NET 3.0, but in 2.0 you can access data w/ XPath expressions by using an XPathNavigator and I doubt this functionality has been removed

From the C# 2.0 docs:
XPathDocument document = new XPathDocument(" path_to/mydocName.xml") ;
XPathNavigator navigator = document.Create Navigator();
XPathNodeIterat or authorNodes = navigator.Selec t("/author/text()");...