1. create script in script library with Hook::ConfigurationPoll name.
2. write your script.

This script will be executed for node after each configuration poll

simple script example

//rename node after configuration poll to snmp sysLocation
//if sysLocation is null then rename to node ip address
//also 3 custom attributes will be setted
// you can use this attributes in events with %{attribute_name} macros
//uncomment trace line and run netxmsd with -D1 param for logging

sub main()
{
  if ($node->isSNMP)
   {
  //trace(1,"hook executed for ".$node->ipAddr);
   transport = CreateSNMPTransport($node);
    if (transport == null)
    {
    //trace(1,"snmp transport error on ".$node->ipAddr);
    return -1;
    }

    location = SNMPGetValue(transport, ".1.3.6.1.2.1.1.6.0"); // sysLocation
    sysname = SNMPGetValue(transport, ".1.3.6.1.2.1.1.5.0");  // sysname
    uptime = SNMPGetValue(transport, ".1.3.6.1.2.1.1.3.0");   // uptime

    //trace(1,"[".location."], [".sysname."], [".uptime."]");

    if (location != null && location !="" && location!=" ")
     {
         //trace(1,"attr location changed to ".location);
         RenameObject($node, location);
     }
    else
    {
         //trace(1,"error in location block");
         RenameObject($node, $node->ipAddr); //change name to node ip address
    }
    if (sysname != null && sysname !="" && sysname !=" ")
    {
         SetCustomAttribute($node, "sysname", sysname); //set custom attribute for node snmp sysName
         //trace(1,"attr sysname changed to ".location);
    }
    else
    {
         //trace(1,"error in sysname block");
    }

    if (uptime != null)
    {
         SetCustomAttribute($node, "uptime", SecondsToUptime(uptime/100)); //set custom attribute uptime for node
         //trace(1,"attr uptime changed to ".SecondsToUptime(uptime/100));
    }
    else
    {
        //trace(1,"error in uptime block");
    }

    //trace(1,"end execution");
    SetCustomAttribute($node, "last_update",localtime(time())->mday.".".localtime(time())->mon.".".localtime(time())->year.", ".localtime(time())->hour.":".localtime(time())->min.":".localtime(time())->sec);
  }
}