what you can do is set up a QTelNet softswitch, it does CDR generation and everything. Don’t know what your budget is but for a 24 port one, will set you back about $6000.00 US. It acts as a means of interfacing SIP and H323 calls together ( YES ! ) and allows you to take in a SIP call and put it out to your provider as H323 or vice-versa. Plus it has a free calling card plugin w/ voice prompts and everything built in. if you want more info, contact me. I’ll give you all the info they gave me when I bought one!
It runs on Win2K as well as linux.
I have even found a way to customize it so that you can export CDR’s as a CSV format for each account number you have plus it automatically sorts by time and date. email me..