procedure TForm1.FormShortCut(var Msg: TWMKey; var Handled: Boolean);
begin
if BeforeCharCode<>VK_MENU then
if Msg.CharCode = Ord( 'A' )
{//Твоя код е тук}
BeforeCharCode:=Msg.CharCode;
end;


BeforeCharCode:Word; - в членовете на TForm1 - private или public.