[Serusers] Textops with AVPs?

Is there a version of textops that can do substs with AVPs that will work on SER 0.9.6 or is that an openSER-only modification of the code? I'm curious because we're ALSO running into the issues of charging the call-forwarding user for forwarding a call to the PSTN instead of charging the calling party. Ideally, I'd like to rewrite the from address solely for the purpose of authenticating the user who's doing the forwarding and charging him for the call, but that would likely break things as there'd be no way to get back to the original user if I just rewrote the from username. SO, I thought, why not let the b2bua handle the details and just forward a uri with a prefix string that includes the user who's forwarding the call (the original RURI instead of just the rewritten one). And there's the trick. How do I craft a RURI out of bits and pieces of things into one long RURI? If it were all the same number, I could use prefix, but it's dynamic (as is the nature of most things), so prefix won't work. How do I take RURI=1105 And add to it: The rewritten RURI from the call forwarding info: 18005551212 AND the prefix for the b2bua auth: 9999 To make: new ruri: 9999110518005551212 N.