you could also do it like this as well to reduce mode flood

ctcp *:unban:?: {
  if ($3 !ischan) { .msg $Nick You must select a channel. | halt }
  var %a = $Ibl($3,0), %b = 0
  while ( %b <= %a ) {
    if ($Ibl($3,%b) iswm $address($2,5)) { var %unbann $addtok(%unbann,$IfMatch,32) }
    inc %b
  }
  mode $3 - $+ $str(b,%b) %unbann
}