C1DataGrid SummaryRow – skip rows

I’m currently using a summary row in my datagrid which is working fine.

<c1:C1DataGrid.BottomRows >
                    <c1:DataGridSummaryRow />
                </c1:C1DataGrid.BottomRows>

Dim dga As New DataGridAggregatesCollection
            Dim sum As New DataGridAggregateSum
            sum.ResultTemplate = DataGridAggregate.GetDataTemplateFromString("{0}")
            dga.Add(sum)
            DataGridAggregate.SetAggregateFunctions(reportGrid.Columns(6), dga)
            DataGridAggregate.SetAggregateFunctions(reportGrid.Columns(7), dga)

My question is, can I skip rows from being counted?

My grid displays certain rows that I don’t want summed up. Is it possible to skip these?

Any help would be greatly appreciated.