string AppDomainAppPath = HttpRuntime.AppDomainAppPath;

            Response.Write(AppDomainAppPath);
            Response.Write("<br/>");

            string path = System.IO.Path.Combine(AppDomainAppPath + "\\File\\MyTemplate.html");

            Response.Write(path);
            Response.Write("<br/>");

            string text = File.ReadAllText(path);

            Response.Write(text);