[Bargest]

Код:

function SysMsgProc(code : integer; wParam : word; lParam : longint) : longint; stdcall; 
begin 
if code = HC_ACTION then 
 begin 
  Wnd := TMsg(Pointer(lParam)^).hwnd; 

  if (Wnd=hd)or(GetParent(Wnd)=hd) then 
    result:=1
  else 
    result:=CallNextHookEx(SysHook, Code, wParam, lParam);
 end; 
end;  

Думаю, как-то так.