[Serusers] Dynamic Routing

Hello All, My task is to program the ser.cfg in a way that it connects to an external database(any machine in LAN,other than the server on which SER is running) After getting connected to the database I need to query the database and get a result set of IPAddresses based on the destination number that I passed in the query..and further use this set to rewrite the call to the IP Address retrieved. To accomplish this task I need-- 1.how to extract the destinationno from sip_uri 2.how to use the database interface given in SER programmer's guide I went through SER programmer's guide,but if anybody can provide me a simple example of using database interface,it wud be of great help. Thanks!