Code:
on *:text:*:#:{
  if ($1 == $seentrigger) {
    var %x $read(" $+ $mircdirmap/seen.text $+ ", w,* $+ $2 $+ *)
    set %tmp.seen $readn
    ;if (%tmp.seen == 1) { goto next } <<-- will be working later if nick not seen..
    var %reg = /.*(\d{10})/
    var %str = $2 (ident@host) was last seen changing nick on to newnick 1099593371
    if ($regex(%str,%reg)) {
      var %stime = $regml(1)
      var %difference = $duration($calc($ctime - %stime))
      msg $chan Last seen: %difference ago
    }
    else {
      echo ERROR.. Can't find last seen time..
    }
  }
}


Try that ? Untested..

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