[Serusers] uri translation based on username

Hello all, I would like to do some changes to the uri based upon the username. I have SIP endpoints with numbered usernames expressing thier location e.g. username 0361234567 I want to make translations to international format but also support local without having to dial 036 International en national are ok, see below. # it is Internationaly if (uri=~"^sip:00") { strip(2); }; # It is NL if (uri=~"^sip:0") { strip(1); prefix("31"); }; Local I am having problems with. I would like to use length but the fucntion does not seem to exist. In addition I run into the problem on how to add "3136" in this case but something else if username is different ? if (uri=~"^sip:[1-9][1-9][1-9][1-9][1-9][1-9][1-9]@") { prefix("some nice trick based on username"); }; any ideas ? thanks, Arne.