[Serusers] Call forwarding to Cisco PSTN GW and correct charging

Has anyone implemented call forwarding from SER to a PSTN CISCO gw? Lets say we have the situation below:

A is caller from PSTN network B is a sip user that forwarded his number to C C is a pstn number

If A calls B then he should be redirected to C , but A should be charged for calling to B , and B should be charged for calling to C.

After some digging in the list and Cisco documents found out about CC-Diversion header and remote party id. What i want to do is to have a cdr created by the cisco machine that fills up the calling number field with A number and the redirecting number field with B number. Which header is the one to use ?

thanks