loadmodule "avpops.so"
modparam("avpops","db_url","mysql://openser:openserrw@localhost/kamailio")
modparam("avpops","avp_table","usr_preferences")

*33 to enable:

  if ($rU=~"^\*33.*") {
      strip(3);
      avp_printf("$avp(s:fwd_blind)","$ruri");
      .......
      avp_db_delete("$from/username","$avp(s:fwd_blind)");
      avp_db_store("$from/username","$avp(s:fwd_blind)");
      sl_send_reply("404","CFWD Set");
      ....}

*32 to disable:

  if ($rU=~"^\*32") {
      avp_db_delete("$from/username","$avp(s:fwd_blind)");
      sl_send_reply("404","CFWD UnSet");
       ......  }

if (avp_db_load("$ruri/username", "$avp(s:fwd_blind)")) {
   $from=$ruri;
   avp_pushto("$ruri", "$avp(s:fwd_blind)");
   ...
   route(RELAY);
   ....