Hi Prasanth,
Please find the below link whihc talks from the UCCE perspective but holds good with UCCX also.
http://www.cisco.com/en/US/partner/prod/collateral/voicesw/custcosw/ps5693/ps427/prod_white_paper0900aecd80648708_ps1844_Products_White_Paper.html
Check for the section "Cisco Agent Desktop Voice Contact Workflow for Call with ANI or Account Number",
Integration Method
1. Telephony Interface - Capturing and Processing Enterprise Data
This section provides a high-level description of the call processing between the IVR application, custom Java method, and Salesforce.com for capturing caller-specific information and using expanded call context (ECC) variables to pass this data to Cisco Agent Desktop.
Hope it helps.
Anand