Как поместить TCheckBox внутри TRichEdit?

Code:

procedure TForm1.FormCreate(Sender: TObject);

{©Drkb v.3(2007): www.drkb.ru}

var

Acb: TCheckBox;

begin

RichEdit1.Left := 20;

Acb := TCheckBox.Create(RichEdit1);

Acb.Left := 30;

Acb.Top := 30;

Acb.Caption := 'my checkbox';

Acb.Parent := RichEdit1;

end;