Use SetFocus method and EditorMode property of DBGrid. Also, you need to send EM_SETSEL message.
procedure TForm1.Button1Click(Sender: TObject); var CurrentWindowFocus: THandle; begin DbGrid1.SetFocus; DbGrid1.EditorMode:=True; CurrentWindowFocus:=Windows.GetFocus; SendMessage(CurrentWindowFocus, EM_SETSEL, 0, 0); end;