<script language="C#" runat="server">

 void Application_BeginRequest(object sender, EventArgs e) {

     string fullUrl = Request.Url.ToString();

     if (fullUrl.Contains("/Courses/coaching.aspx"))
     {
         Context.RewritePath("Courses.aspx?GroupID=17&CourseName=Coaching");
     }
     else if (fullUrl.Contains("/Courses/Finance.aspx"))
     {
         Context.RewritePath("/Courses.aspx?GroupID=25&CourseName=Finance");
     }

}
</script>