[NumLock]

Код:

procedure ShortCutToModifiersKey(ShortCut: TShortCut;
  var Modifiers: Cardinal; var Key: Cardinal);
begin
  Key := ShortCut and not (scShift + scCtrl + scAlt);
  Modifiers := 0;
  if ShortCut and scShift <> 0 then Modifiers := Modifiers or MOD_SHIFT;
  if ShortCut and scCtrl <> 0 then Modifiers := Modifiers or MOD_CONTROL;
  if ShortCut and scAlt <> 0 then Modifiers := Modifiers or MOD_ALT;
end;

Код:

var
  Modifiers: Cardinal;
  Key: Cardinal;
begin
  ShortCutToModifiersKey(HotKey1.HotKey, Modifiers, Key);
  RegisterHotKey(Handle, 1, Modifiers, Key);
end;