[Serusers] Iconnect

Hi, I was wondering if something like this could be possible with SER: If we use SER as the SIP server for a small company and they wanted to have access to a SIP PSTN Gateway, could we just open an account with Iconnect or Vonage and have all the company's PSTN traffic be redirected to the Iconnect SIP gateway by SER (SER would have to rewrite the INVITE so that the originator has the username/password of the account that we setup). In the eyes of Iconnect or Vonage the calls would be coming in from one user(the account that we opened). I know this is a little extreme but seeing that SER can rewrite and manipulate so many other things, maybe it could do this as well. Thanks, Ricardo