You can use these instructions to add a IPS sensor to CSM (they haven't changed much since 3.x) if you need better or more current instructions, hit the "HELP" link on your CSM screen:
http://www.cisco.com/en/US/partner/products/ps6498/products_tech_note09186a0080846d67.shtml
CSM does not forward events, but you CAN connect your SIEM directly to your sensor if your SIEM has an SDEE client. The sensor can support up to 4 or 5 simultaneous clients, providing each of them an event feed. (the IPS Sensor is an SDEE server)
- Bob