Hi, I got a solution, but I would like knows if it is a nice solution.
My code:
        #region Custom Redirect
        string strCustomPath;
        string strCurrentPath = Request.Path.ToLower();
        // Search the page to fire the rewriter
        if (strCurrentPath.ToLower().IndexOf("rentals.rt") > -1)
        {
            string parametros = string.Empty;
            // Search the parameters by querystring
            if (URLRewriter.CurrentURL.IndexOf('?') > -1)
                parametros = URLRewriter.CurrentURL.Substring(URLRewriter.CurrentURL.IndexOf('?'));
            // new path
            strCustomPath = string.Format("/rentals.aspx{0}", parametros);
            // Rewrite the URL
            Context.RewritePath(strCustomPath);
        }
        #endregion
The url will be www.mysite.com/country/state/rentals.rtl?a=1&b=2&c=3 but the page called is /rentals.aspx.