Title: Set focus to DBGrid for editing
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;