[OpenSER-Users] avp_subst and regex

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. -- Zahid