Pivot Table - Conditional Format Query

Hiya

I have a pivot table that is initially displayed to list employee names in rows, and the "hours type" (Earned or Taken) in columns.

Earned hours are a positive figure and Taken are negative. The Grand Total column displays the sum of Earned and Taken - so if employee John Smith had "Earned" 3.00 hours and "Taken" -2.50 hours, then the Grand Total column would display 0.50.

The Grand Total figure SHOULD never be a negative, as employees must earn their hours before they take them, but in order to clearly highlight any instances where an employee has taken more than they have earned, I'd like to format the Grand Total column to highlight in red any instances where the figure in that column is less than zero.

I can select the range and apply the formatting without difficulty to the pivot table "starting position", but when the fields are re-arranged, the conditional formatting remains in the area specified.

Is there any way to set up the Grand Total field on a Pivot Table so that the conditional formatting remains in the Grand Total column, irrespective of what column number the Grand Total may currently be??

Hope this makes sense....

JAF