GridBoundControl formulas

I have a bound grid and need to provide summary row is different sections. The questionable part is that the data to be summed is every 8 rows apart for a section. Is there an ideal way to accomplish this with formulas?

This would be difficult using a GridDataBoundGrid as there is no concept of unbound rows in GridDataBoundGrid. You cannot just easily insert rows into a GridDataBoundGrid whose values do not come from the bound datasource. It would be easier to use a ''mixed'' virtual GridControl to handle this task. You could use QueryCellInfo to display the values in the grid from the DataTable leaving every 8th row avaiable for use as a formula row. Depending on how many rows we are talking about here, you may or may not want to provide the formula rows in some virtual manner. If you do choose to use the formula rows in a virtual manner, you woul dhave to manage a FormulaTag collection as in the KB article referring to using formulas in aGridDataBoundGrid which is a type of virtual grid. http://www.syncfusion.com/Support/article.aspx?id=10439