Crystal Reports for Eclipse Designer Guide
Viewing and modifying custom functions
Once you've created a custom function, you can view or modify it at any time.
In this section:
To modify a custom function
SAP BusinessObjects
http://www.sap.com/sapbusinessobjects/
Support services
http://service.sap.com/bosap-support/
Product Documentation on the Web
http://help.sap.com/