SiteMapNode for an entire directory?

[ryanmhuc@yahoo.com]

I would like to create a tab menu navigation where all pages under a
directory are considered under a specific tab. So when under any page
in a directory its tab is considered selected. I have created a tab
menu using asp:menu, used the sitemapnodes, and created a tab
navigation that where when on the specified page (SiteMapNode) the tab
is selected. I did using the following tutorial

http://dotnet.sys-con.com/read/86222.htm

Is it possible to specify that any page under a directory will cause
the asp:menu to think a particular sitemapnode is selected? This way
only the top level pages are needed in the sitemap and never needs to
be updated again. Thanks