unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls,
  Forms, Dialogs, Menus;

type
  TForm1 = class(TForm)
    MainMenu1: TMainMenu;
    One1: TMenuItem;
    Two1: TMenuItem;
    THree1: TMenuItem;
  private
    {Private declarations}
    procedure WmMenuChar(var m : TMessage); message WM_MENUCHAR;
  public
  {Public declarations}
end;

var
  Form1: TForm1;

implementation
{$R *.DFM}

procedure TForm1.WmMenuChar(var m: TMessage);
begin
  Form1.Caption := 'Non standard menu key pressed';
  m.Result := 1;
end;

end.