Order Admin sub-menu items?

Question

I am adding items to a CPT Admin menu using add_submenu_page which works great, but they are added to the bottom of the sub-menu after the CPT options. I want to be able to have them on top , but I suppose this question can also apply to ordering all Admin based sub-menu items.

What I tried ( not working, I tried several variations),

function custom_menu_order($menu_ord) {
       if (!$menu_ord) return true;

       return array( 

         'edit.php?post_type=page' =>array(
                                      'edit.php?post_type=note',
                                      'edit_pages',
                                      'notes',
                                      )   
                    );
}

add_filter('custom_menu_order', 'custom_menu_order');
add_filter('menu_order', 'custom_menu_order');

Would this be because menu_order filter does not take sub-menu's into account?