[OpenSER-Users] regex syntax?

Hi, I've got a question, I have some really stupid ATAs that can't do proper DNS lookups and are are a bit retarded when it comes to making calls. Unlike other systems, if I put sipserver.mobilia.it in as the proxy/registrar, it decides that its domain is also sipserver.mobilia.it. While registering that isn't too much of a problem, but when I send calls to PSTN termination (through a carrier), they'll accept(a)mobilia.it or other domains.. but they don't seem to want @sipserver.mobilia.it. Instead of asking my carrier to make an exception, I figured it should be fairly easy to just drop the sipserver from the ruri, and let it be.. I'm just not sure if I'm getting the sysntax right.. this should do the trick, right? BTW openser 1.1.1 and code borrowed from openser wiki. subst_uri('/^sip:[0-9]{8,24}@(sipserver.*)$/sip:\1@mobilia.it;orig_uri=\0/i')