That is a very very inefficient and longwinded way of doing this.

Code:
on *:start:{ check }
alias check {
  var %dlls = x.dll y.dll z.dll, %i = 1
  while ($gettok(%dlls,%i,32) != $null) {
    if (!$isfile($+($scriptdir,dlls\,$v1))) { echo $color(info) -a * $gettok(%dlls,%i,32) appears to be missing. }
    inc %i
  } 
}