cxgrid footer summary value by a column

var
  AIndex: integer;
  AValue: variant;
begin
 with cxGrid1DBTableView1.DataController.Summary do
    begin
      AIndex :=  DefaultGroupSummaryItems.IndexOfItemLink(cxGrid1DBTableView1DBColumn2);
      AValue :=  DefaultGroupSummaryValues[AIndex]
    end;
  pplabel6.Caption := VarToStr(AValue);

var
  AIndex, AGroupIndex: integer;
  AValue: variant;
begin
  with <AcxGridDBTableView>.DataController do
  begin
    AGroupIndex := Groups.DataGroupIndexByRowIndex[<ARowIndex>];
    AIndex := Summary.DefaultGroupSummaryItems.IndexOfItemLink(<AColumn>);
    AValue := Summary.GroupSummaryValues[AGroupIndex, AIndex];
  end;
  Caption := VarToStr(AValue);
end;