How to customize the summary column for specific rows in WinForms GridGroupingControl?

void gridGroupingControl1_QueryCellStyleInfo(object sender, GridTableCellStyleInfoEventArgs e)
{
    switch (e.TableCellIdentity.TableCellType)
    {
        case GridTableCellType.SummaryFieldCell:
                {
                    if(e.TableCellIdentity.SummaryColumn.Name == "Data1")
                    {
                       e.Style.CellType = GridCellTypeName.FormulaCell;
                       e.Style.CellValue = "=SUM(B2:B5)"; //To summarize specific rows(First three rows)
                    }
                    break;
                }
     }
}

Private Sub gridGroupingControl1_QueryCellStyleInfo(ByVal sender As Object, ByVal e As GridTableCellStyleInfoEventArgs)
   Select Case e.TableCellIdentity.TableCellType
      Case GridTableCellType.SummaryFieldCell
               If e.TableCellIdentity.SummaryColumn.Name = "Data1" Then
                  e.Style.CellType = GridCellTypeName.FormulaCell
                  e.Style.CellValue = "=SUM(B2:B5)" 'To summarize specific rows(First three rows)
               End If
      Exit Select
   End Select
End Sub