[NumLock]

Код:

type
  TForm1 = class(TForm)
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    procedure WMHOTKEY(var Message: TMessage); message WM_HOTKEY;
  end;
...
procedure TForm1.FormCreate(Sender: TObject);
begin
  RegisterHotKey(Handle, 2015, MOD_ALT, Ord('H'));
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  UnregisterHotKey(Handle, 2015)
end;

procedure TForm1.WMHOTKEY(var Message: TMessage);
begin
  inherited;
  if Message.WParam=2015 then SetForegroundWindow(Handle);
end;