Why don't you use $ialchan? Then loop through the matches.

Using $ialchan(*!*@*,$chan,0).nick for example:

Code:
On *:Ban:#: {
  var %x = 1
  while (%x <= $ialchan($banmask,$chan,0)) {
    echo -a $ialchan($banmask,$chan,%x).nick
    inc %x
  }
}


Just change the echo bit to how you stored the nicknames before.