Asp.net web forms routing to virtual item
===

I am trying to create a route in routetable that routes to a virtual item (using a cms that creates url like site.com/about/company, where there is no physical file called company exists) using system.web.routing (unfortunately i cannot use iis rewriting/routing). I have tried the following but it results in 404. If I were to point to another physical file (tor testing purpose), the routing works fine. 

    void RegisterRoutes(RouteCollection routes)
    {
        routes.RouteExistingFiles = true;
        routes.MapPageRoute("about", "about/us", "~/about/company", false);
    }

So, is it possible to point to an item like that?