[Serusers] function capable of identifying the domain of the callee

Hi, I'm looking for a function capable of identifying the domain of the callee so I can implement something like this: if(domain_of_callee == domain_A) { do this } if(domain_of_callee == domain_B) { do that } I know that there are some functions like those in textops module, but the problem is that I can't search in the INVITE messages for that because I what that to be searched in INVITE messages sent from Ser to Asterisk for Voicemail purpose, and in that cases, the domain of the callee was already replaced by the IP of Asterisk server in those messages, and To and From parameters can have other domains because I'm using multi-domain implementation. Is there a function that does this? Thanks, Ricardo.