1. Open the administration page for your Excel
Services Application.
2. Select Trusted file locations.
3. Select Add Trusted File Location in the top
navigation bar.
4. Enter the address for the accounting
subsite in the Address field.
5. Select that the location is a SharePoint
site.
6. Enable the option to trust child libraries
or directories by checking the Children trusted
box.
7. Enter a volatile function cache lifetime
value of 300 (5 minutes).
8. Set the Allow External Data option to
Trusted data connection libraries and embedded sources.
9. Select to allow user-defined functions in
the Allow User Defined Functions section.
10. Click OK.