Alternative way to change data in Pivot Table

Hi,

Unlike normal tables, we can't change the data in a pivot (ie total clients
in a city). If I double click on a particular figure, it will bring me to a
new tab with all the details listed. If I try to delete, it saysthat I can't
change this part of a report.

Let's say my data is down to the city level and the user is able to play
with the pivot and choose different grouping level (ie state/Country).
Anyways, I only want to allow the user to change the number of clients of a
city. Thus one criteria to check is to ensure the user is trying to make a
change to a city and not a state/country. There's also other info about the
cities, but the change is only allowed to the number of clients field.

What can I do?

Thanks,
Carmen