Simulink 'File' menu customization

Hello all

I need to customize the interface of a simulink library and the block diagrams which I have created recently, I need to add some menu items in the 'File->New' menu (not in 'Simulink:FileMenu', sl_customization), but could not get any way to do this (there aren't get methods in sl_customization_manager returning the built-in menus schema functions) Any suggestion?, please help.

Thanks, Gagik