"Format"? Problem with thousand separator

Hello

When working with large numbers the "thousand separator" doesnt work for the whole number, of example:

Original Number: 2800000000

Expected Result: 2.800.000.000

Result Obtained: 2800000,000.00

I hope the separator could be a dot but a comma works just fine.

I am using Office 2007 and the Crystal Ball add-on

Any ideas on how to make this work?

Thanks a lot for your help