[Freeswitch-users] Manipulate sip error codes

Hi, Is it possible to translate B leg sip error codes so that the A leg always gives a fixed error code? i.e make call and get 408 for instance from the far end but would like 486 to be sent on the a leg. Need this as one of our suppliers retransmits a call multiple times unless they recieve a 403 or 486. No major issue but just clogs the error cdrs with loads of duplicate records otherwise. Any ideas would be greatly appreciated. Many thanks Chris