[NumLock]

Код:

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
    procedure WMHOTKEY(var Msg: TMessage); message WM_HOTKEY; 
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
  RegisterHotKey(Handle, 1, MOD_CONTROL, VK_DOWN);
  RegisterHotKey(Handle, 2, MOD_CONTROL, VK_UP);
end;

procedure TForm1.WMHOTKEY(var Msg: TMessage);
begin
  case Msg.WParam of
    1: MessageBox(Handle, 'Ctrl+Down', 'WMHOTKEY', MB_OK or MB_SYSTEMMODAL);
    2: MessageBox(Handle, 'Ctrl+Up', 'WMHOTKEY', MB_OK or MB_SYSTEMMODAL);
  end;
end;

end.