URL routing - opposite of GetRouteUrl in Asp.net webform
<p>Assume I have the following defined in global.asax:</p>

<pre><code>routes.MapPageRoute("about", "about", "~/About.aspx");
</code></pre>

<p>In an ashx file, I want to be able to pass in "about" and return "~/About.aspx".  I know the opposite can be done via GetRouteUrl, but is there a built-in function for what I'm looking to do?</p>
