Hello, indeed there seems to be an issue with interpreting the strings in config file, before getting to avpops function parameters. When the config file is parsed, inside the string, \[0-7]{2,3} is interpreted as a ASCII code in octal base and replaced with its code. Try: avp_subst("$avp(s:fromuri)","/^(sip:)([134][0-9]{4}@.*)/\\\x01121285 \2/"); However, in 1.2 you can achieve same by: $avp(s:fromuri) ="sip:121285"+$(avp(s:fromuri){uri.user}) + "@" + $ (avp(s:fromuri){uri.domain}); Cheers, Daniel On 08/01/07 19:06, Zahid Mehmood wrote: > Hi, > I am trying to rewrite a 5 digit number to a 11 digit number by > adding a prefix "121285". To achieve that I use the following: > > > avp_subst("$avp(s:fromuri)","/^(sip:)([134][0-9]{4}@.*)/\1+121285 > \2/"); > > in openser.log new fromuri = sip:+12128512345@host.columbia.edu > > It works fine because of the "+" after \1 > > This avp_subst does not work properly if the "+" is taken out. > How can I use "\1" followed by another digit? > > avp_subst("$avp(s:fromuri)","/^(sip:)([134][0-9]{4}@.*)/\1121285 > \2/"); > > in openser.log: new fromuri = J128512345(a)host.columbia.edu > > > What am i doing wrong? > > Thanks in advance for your help. >