[Serusers] Is there a way to strip ";cic=nnnn" from INVITES?

I am receiving intermittent INVITES from a couple of sources where the INVITE includes a cic=nnnn. I need to strip this off before it reaches the PSTN gateway switch because that switch will try to use that value. However, it appears to be a pseudo-CIC and isn't an assigned carrier number so it can't be used for routing outside the network that stuck it in there. That network should be stripping it off before the call leaves their network, but they are not and the call has passed through a few entities by the time it reaches us, so we don't know whom to contact about the problem. Does SER have any mechanism that will strip this ONE item and leave the rest of the INVITE intact, eg so I can call more than one hard-coded number? The documentation I examined (iptel.org SIP Express Router v0.11.0 -- Admin's Guide, chapter 2.3, page 22) shows functions to delete or replace everything but attributes following a semi-colon and preceding the @. Is there something that is undocumented? Sample: (values altered) INVITE sip:9615551212;cic=9234@208.37.38.39;user=phone SIP/2.0 Need to change that to: INVITE sip:9615551212@208.37.38.39;user=phone SIP/2.0 (and leave any other parameters that might be present intact.) Thanks in advance for suggestions.