How to assign unique ID to MC60 modules

We have got MC60 modules with 15 digit IMEI number, but we want to assign 10digit ID to each module for our internal unique identification purpose. How can I assign 10digit unique ID to each module which we need to retrieve from the firmware?

get first 10 digits from IMEI
Structure of the IMEI … AA-BBBBBB-CCCCCC-D- is serial number