var
 ScrPt, GrdPt: TPoint;
 Cell: TGridCoord;
begin
 ScrPt := Mouse.CursorPos;
 GrdPt := DBGrid.ScreenToClient(ScrPt);
 Cell := DBGrid.MouseCoord(GrdPt.X, GrdPt.Y);
 // Col := Cell.X;
 // Row := Cell.Y;
end;
 ...
 FieldText: string;
 DLink: TDataLink;
 OldActiveRec: Integer;
 ...
 Cell := DBGrid.MouseCoord(GrdPt.X, GrdPt.Y);
 FieldText := '';
 DLink := THackDBGrid(DBGrid).DataLink;
 if Assigned(DLink) then
 begin
  if (Cell.X < = 0)or(Cell.Y < = 0) then Exit;
  OldActiveRec := DLink.ActiveRecord;
  try
  DLink.ActiveRecord := Cell.Y-1{TitleOffset};
  FieldText := DBGrid.Columns[Cell.X-1{IndicatorOffset}].Field.Text;
  finally
  DLink.ActiveRecord := OldActiveRec;
  end;
 end;