Hello,
Check on cisco's website about a document called features and services for CUCM 7.1 , there is a feature could help your case called CMC (Client Matter Code) , here is a brief about it :
To use the Client Matter Codes feature, users must enter a client matter code to reach certain dialed numbers. You enable or disable CMC through route patterns, and you can configure multiple client matter codes. When a user dials a number that is routed through a CMC-enabled route pattern, a tone prompts the user for the client matter code. When the user enters a valid CMC, the call occurs; if the user enters an invalid code, reorder occurs. The CMC writes to the CDR, so you can collect the information by using CDR Analysis and Reporting (CAR), which generates reports for client accounting and billing.
The Client Matter Codes feature benefits law offices, accounting firms, consulting firms, and other businesses or organizations where tracking the length of the call for each client is required. Before you implement CMC, obtain a a list of all clients, groups, individuals, parties, and so on that you plan to track through CMC. Determine whether you can assign the codes consecutively, arbitrarily, or whether your organization requires a special code structure; for example, using existing client account numbers for CMC. For each client (or group, individual, and so on) that you want to track, you must add a client matter code in the Client Matter Code Configuration window of Cisco Unified Communications Manager Administration. Then, in Cisco Unified Communications Manager Administration, you must enable CMC for new or existing route patterns. After you configure CMC, make sure that you update your dial plan documents to indicate the CMC-enabled route patterns.
Amer
