CCX 7.x is still on the Windows platform and uses MSDE or Microsoft SQL 2000 depending on the deployment scenario.
Your only supported path for custom reports is to design them in Crystal, add the stored procedures, and then run them through the HRC.
Historical Reporting Administrator and Developer Guide for Cisco Unified CCX and Cisco Unified IP IVR, Release 7.0(1)
http://cisco.com/en/US/docs/voice_ip_comm/cust_contact/contact_center/crs/express_7_0/programming/guide/uccx70hradmdev.pdf