[[oscarac]]

Yo hice algo similar a lo que tu mencionas de la siguiente manera

Código Delphi [-]
 
Procedure TfrmBalanceGasto.ExportarToExcel(fName: string);
const
  xlWBATworksheet = -4167;
var
  Excel, WorkBook, WorkSheet: OleVariant;
  I, J, _FilaIni, _quiebre, _FilaTitulos: Integer;
  _Campo :String;
  _f, _c :Integer;
  _posiciones :array [1..10] of Integer;
  const _letras :array [1..13] of string = ('C','D','E','F','G','H','I','J','K','L','M','N','O');
begin
  _FilaTitulos := 6;
  _Campo := '';
  Excel := CreateOleObject('Excel.Application');
  Excel.DisplayAlerts := False;
  WorkBook := Excel.Workbooks.Add(xlWBATWorksheet);
  WorkSheet := WorkBook.WorkSheets[1];
  WorkSheet.Name := 'Hoja1';
  WorkSheet.Cells[1,1].font.Bold := True;
  WorkSheet.Cells[1,1] := dmGlobal.g_NombreEmpresa;
  WorkSheet.Cells[2,1] := 'R.U.C. : ' + dmGlobal.g_RUCEmpresa;
  WorkSheet.Cells[3,1].font.Bold := True;
  WorkSheet.Cells[3,1] := 'Consolidado Anual de Gastos';
  WorkSheet.Cells[4,1] := iif (rgRango.ItemIndex = 0, 'Mensual del mes de ','Acumulado al mes de ') +  NombreMes(StrToInt(dmGlobal.g_Mes));
  WorkSheet.Cells[5,1] := 'Cuenta 9' + edtDigito.Text;
  worksheet.range['A3:O5'].HorizontalAlignment := xlHAlignCenterAcrossSelection;
  WorkSheet.cells[_FilaTitulos,1] := 'Cuenta';
  WorkSheet.cells[_FilaTitulos,3] := 'Enero';
  WorkSheet.cells[_FilaTitulos,4] := 'Febrero';
  WorkSheet.cells[_FilaTitulos,5] := 'Marzo';
  WorkSheet.cells[_FilaTitulos,6] := 'Abril';
  WorkSheet.cells[_FilaTitulos,7] := 'Mayo';
  WorkSheet.cells[_FilaTitulos,8] := 'Junio';
  WorkSheet.cells[_FilaTitulos,9] := 'Julio';
  WorkSheet.cells[_FilaTitulos,10] := 'Agosto';
  WorkSheet.cells[_FilaTitulos,11] := 'Setiembre';
  WorkSheet.cells[_FilaTitulos,12] := 'Octubre';
  WorkSheet.cells[_FilaTitulos,13] := 'Noviembre';
  WorkSheet.cells[_FilaTitulos,14] := 'Diciembre';
  WorkSheet.cells[_FilaTitulos,15] := 'Total';
  worksheet.range['A5:O5'].HorizontalAlignment := xlHAlignCenter;
  i:= _FilaTitulos + 1;
  _FilaIni := i;
  _quiebre := 0;
  DBGrid1.DataSource.DataSet.First;
  _Campo := Izquierda(DBGrid1.Fields[0].AsString, StrToInt(edtDigito.Text));
  while not DBGrid1.DataSource.DataSet.Eof do
  begin
    for J := 0 to DBGrid1.FieldCount -1 do
      case DBGrid1.Fields[J].DataType of
        ftAutoInc, ftBytes, ftInteger, ftSmallint, ftWord: // Auto o Numérico
          WorkSheet.Cells[I, J +1] := DBGrid1.Fields[J].AsInteger;
        ftBCD, ftFloat, ftCurrency: // Numérico con decimales
          WorkSheet.Cells[I, J +1] := DBGrid1.Fields[J].AsFloat;
        ftDateTime, ftDate, ftTime: // Fecha y Hora
          WorkSheet.Cells[I, J +1] := DBGrid1.Fields[J].AsDateTime;
        else // Todo lo demas caracteres
          WorkSheet.Cells[I, J +1] := DBGrid1.Fields[J].AsString;
      end;
      inc (i);
      ProgressBarXls.Position := ProgressBarXls.Position +1;
      DBGrid1.DataSource.DataSet.Next;
      if edtDigito.Text <> Derecha(dmGlobal.g_NivelCuenta,1) then
        begin
          if (_Campo <> Izquierda(DBGrid1.Fields[0].AsString, StrToInt(edtDigito.Text))) or (DBGrid1.DataSource.DataSet.Eof) Then
            begin
              _Campo := Izquierda(DBGrid1.Fields[0].AsString, StrToInt(edtDigito.Text));
              WorkSheet.cells[i,3] := '=Sum(C' + IntToStr(_Filaini) + ':C' + IntToStr(i-1) + ')';
              WorkSheet.cells[i,4] := '=Sum(D' + IntToStr(_Filaini) + '' + IntToStr(i-1) + ')';
              WorkSheet.cells[i,5] := '=Sum(E' + IntToStr(_Filaini) + ':E' + IntToStr(i-1) + ')';
              WorkSheet.cells[i,6] := '=Sum(F' + IntToStr(_Filaini) + ':F' + IntToStr(i-1) + ')';
              WorkSheet.cells[i,7] := '=Sum(G' + IntToStr(_Filaini) + ':G' + IntToStr(i-1) + ')';
              WorkSheet.cells[i,8] := '=Sum(H' + IntToStr(_Filaini) + ':H' + IntToStr(i-1) + ')';
              WorkSheet.cells[i,9] := '=Sum(I' + IntToStr(_Filaini) + ':I' + IntToStr(i-1) + ')';
              WorkSheet.cells[i,10] := '=Sum(J' + IntToStr(_Filaini) + ':J' + IntToStr(i-1) + ')';
              WorkSheet.cells[i,11] := '=Sum(K' + IntToStr(_Filaini) + ':K' + IntToStr(i-1) + ')';
              WorkSheet.cells[i,12] := '=Sum(L' + IntToStr(_Filaini) + ':L' + IntToStr(i-1) + ')';
              WorkSheet.cells[i,13] := '=Sum(M' + IntToStr(_Filaini) + ':M' + IntToStr(i-1) + ')';
              WorkSheet.cells[i,14] := '=Sum(N' + IntToStr(_Filaini) + ':N' + IntToStr(i-1) + ')';
              WorkSheet.cells[i,15] := '=Sum(O' + IntToStr(_Filaini) + ':O' + IntToStr(i-1) + ')';
              Inc(_quiebre);
              _posiciones [_quiebre] := i;
              Inc(i);
              _FilaIni := i;
            end;
        end;
  end;
  if _posiciones[1] <> 0 then
    Begin
      for _c := 1 to 13 do
        Begin
        _Campo := '';
        for _f := 1 to 10 do
          if _posiciones [_f] <> 0 then
            _Campo := _campo + '+' + _letras[_C]  + IntToStr(_posiciones[_f]);
            WorkSheet.cells [i,2 + _c] := '= Sum( ' + _Campo + ')';
        End;
    End;
  WorkSheet.Cells.Columns.AutoFit;
  WorkBook.SaveAs(fname);
  WorkBook.Close(fName);
  Excel.Quit;
end;

lo que si debes tener cuidado es en la version del excel que tengas.. he visto algunos casos en que se debe colocar =SUMA... en lugar de =SUM