procedure TForm1.StringGrid1DrawCell(Sender: TObject; ACol, ARow: Integer;
  Rect: TRect; State: TGridDrawState);
begin
  if gdFixed in State then StringGrid1.Canvas.Brush.Color := clGray
                      else StringGrid1.Canvas.Brush.Color := clWhite;
  StringGrid1.Canvas.FillRect(Rect);
  if ((ACol <>  2 ) or (ARow <>  0 )) and ((ACol <>  3 ) or (ARow <>  0 )) then
      StringGrid1.Canvas.Rectangle(Rect.Left- 1 , Rect.Top- 1 , Rect.Right, Rect.Bottom);
  if (ACol =  3 ) and (ARow =  0 ) then begin
    StringGrid1.Canvas.TextOut(Rect.Left - StringGrid1.ColWidths[aCol -  1 ], Rect.Top, 'mmmmmmmmmmmmmmmmmmm');
  end;
end;