CacheIndex Property
Returns or sets the index number of the PivotTable cache. Read/write Long.
Remarks
If you set the CacheIndex property so that one PivotTable report uses the cache for a second PivotTable report, the first report’s fields must be a valid subset of the fields in the second report.
Example
This example sets the cache for the PivotTable report named "Pivot1" to the cache of the PivotTable report named "Pivot2."
Worksheets(1).PivotTables("Pivot1").CacheIndex = _
Worksheets(1).PivotTables("Pivot2").CacheIndex