um you have msg %botchan and there is no way of setting that on ur script.
or you can do it all like this

on *:text:!peak:#: {
  msg $chan $iif($($+(%,peak,$nick,$chan),2),4 $+ $chr(44) $+ 8Please wait 30seconds before checking Peak Users again.,7Most users to chat on4 $chan 7is4 $($+(%,mostusers,$chan),2) 7on4 $($+(%,$chan,mostusers),2)) 
  set -u30 $+(%,peak,$nick,$chan) wait
}
on *:load: {
  echo -a Welcome to !peak script By PuNkTuReD
  echo -a Type !peak to check Channel Peak
}
on !*:join:#: { 
  if ($nick($chan,0) > $($+(%,mostusers,$chan),2)) || (!$($+(%,mostusers,$chan),2)) { 
    set $+(%,mostusers,$chan) $nick($chan,0) 
    set $+(%,$chan,mostusers) $date(mm/dd/yy)
  } 
}

but anyway nice work 6/10