GrandTotalName Property
Returns or sets the text string label that is displayed in the grand total column or row heading in the specified PivotTable report. The default value is the string "Grand Total". Read/write String.
Example
This example sets the grand total heading label to "Regional Total" in the second PivotTable report on the active worksheet.
ActiveSheet.PivotTables("PivotTable2").GrandTotalName = "Regional Total"