How do I access subtotals from a pivot?

I've got a pivot with an av开发者_运维技巧erage value and I need to be able to access it in another spreadsheet, how can I do this? It seems like I cannot access any subtotals.

Heres the value of the cell:

=GETPIVOTDATA($A$3,"'1/2/2011 - 1/8/2011' operation_id['4';Data,Average] 'Sum of Estimated Hours / Paid Per Operation'")

Mousing over the #REF seems to indicate that there are missing or deleted cells but I haven't deleted anything.

http://office.microsoft.com/en-us/access-help/about-calculating-totals-in-pivottable-view-HP003084426.aspx

"Callout 1 The Sum of Sales total field. You cannot add total fields to the row, column, or filter area."