Small error on my part. Here's the corrected code with the nick requirement.
Code:
 on *:text:!count*:#:{
  if ($nick == <nick>) {
    if !$2 {
      .msg $nick Format is !count <high number> <interval>
      .msg $nick <interval> will default to 1 if not supplied
    }
    var %rpt = $calc($2 / $iif(!$3,1,$3))
    if $abs(%rpt) != %rpt {
      .msg $nick Sorry, but I'll never reach $2 using increments of $iif(!$3,1,$3)
    }
    else {
      var %count = 1
      while %count <= $2 {
        describe $chan %count
        inc %count $iif(!$3,1,$3)
      }
    }
  }
}


Replace <nick> with the appropriate nick