Creating a Desensitised Copy of a Power Pivot Workbook

I have been working with a client here in Sydney were we are producing some Human Resource (HR) reporting tools to analyse what is happening across the business. HR data is quite often very sensitive because it can contain personal information as well as salary information. A lot of the calculations that are in the workbook we have been building do not require all this sensitive information to work - eg Total New Employees, Total Employees leaving the business etc. The reports are going to work if the sensitive data is in or out, but some people are allowed to have the sensitive data and others are not. So..what to do?!