Components for Delphi and C++ Builder.

procedure TForm1.Button3Click(Sender: TObject);
var
  r: TRect;
  p: TPoint;
begin
  r := DBGridEh1.CellRect(DBGridEh1.Col,DBGridEh1.Row);
  p := DBGridEh1.ClientToScreen(Point(r.Left, r.Bottom));
  PopupMenu1.Popup(p.X, p.Y);
end;

TRect r = dbgeh->CellRect(dbgeh->Col,dbgeh->Row);
TPoint p = dbgeh->ClientToScreen(Point(r.Left,r.Bottom));
ppm->Popup(p.x, p.y);