THotKey控件和RegisterHotKey控件的配合使用

我想注册一系统热键，但不在设计时注册，要在运行时通过按“设置”按钮，将THotKey1
组件中用户选定的组合键（比如：Ctrl+A；或Alt+Ctrl+R）设为系统热键（用RegisterHotKey)。请问该怎么样做？急用。
下面是Kingron的回答：
unit Unit1;
{ Copyright Kingron 2002 }
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, Grids, ValEdit, StdCtrls, ExtCtrls, ComCtrls;
type
TForm1 = class(TForm)
LabeledEdit1: TLabeledEdit;
HotKey1: THotKey;
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
Key,Shift:Word;
procedure wmhotkey(var Msg:TMessage);message WM_HOTKEY;
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
uses
Menus;
function ShiftStateToWord(Shift:TShiftState):Word;
begin
if ssShift in Shift then Result :=MOD_SHIFT;
if ssCtrl in Shift then Result :=Result or MOD_CONTROL;
if ssAlt in Shift then Result:=Result or MOD_ALT;
end;
procedure TForm1.Button1Click(Sender: TObject);
var
T:TShiftState;
begin
ShortCutToKey(HotKey1.HotKey,Key,T);
Shift :=ShiftStateToWord(T);
RegisterHotKey(Handle,GlobalAddAtom('MyHotKey') - $C000,Shift,Key);
end;
procedure TForm1.wmhotkey(var Msg: TMessage);
begin
if (Msg.LparamLo = Shift) AND (Msg.LParamHi = Key) then
ShowMessage('OK');
end;
end.