Getpivotdata question

Dear All,

I have created a calculated field named "Less than plan" in the attached pivot table. calculated field.xlsx

The formula is:

=IF((Actual-Original)<0,Actual-Original,0)

I want to get the sum of individual rows through a Getpivotdata formula because formula is also applied to the grand total of calculated field which is incorrect.

The answer is sum of -6,500 of cell range CV6:CV58 which i need to obtain form Getpivotdata formula.

Please help me on this.

Kindly help me please