It's not particularly well known, but to create custom reports, you need the iAR (Intelligent Analysis Reporter) module:
http://h17007.www1.hp.com/us/en/networking/products/network-management/IMC_IAR_Software/index.aspxThis is basically Crystal Reports, and it lets you create your own custom .RPT files.
Note: iAR is a separately licensed module. If you don't have the license installed, you can create custom reports, but you won't be able to upload them. iAR itself is installed on a separate Windows PC, to create the .RPT files., but then it is not needed for actually running the reports.