ASP.Net MVC RedirectToAction with anchor

I have the following problem: For example I have route like this:

routes.Add(new Route("forums/thread/{threadOid}/last", new MvcRouteHandler())
           Defaults = new RouteValueDictionary(
             new { controller = "Thread", action ="ShowThreadLastPostPage"}),
        Constraints = new RouteValueDictionary(new { threadOid = @"^\d+$" })
    }
);

Is there a way using RedirectToAction method navigate to the URL like this:

> forums/thread/{threadOid}/last#postOid

I think you should use the Redirect method along with Url.RouteUrl to accomplish it.

return Redirect(Url.RouteUrl(new { controller = "Thread", action = "ShowThreadLastPostPage", threadOid = threadId }) + "#" + postOid);

Another alternative with Url.Action:

return Redirect(Url.Action("ShowThreadLastPostPage", "Thread", new { threadOid = threadOid }) + "last#" + postOid);