@ the risk of sounding condescending, yet again. $modespl is pointless and moot, in a remote, unless you either loop or the user already knows the max.
To use $modespl and not be pointless you'd need something like

;set your vars
  var %i = 1, %os
;set loop max to names
  while (%i <= $numtok($2-,32)) {
;add a name
    %os = %os $gettok($2-,%i,32)
;are we @ max yet?
    if ($numtok(%os,32) == $modespl) { 
;we're @ max so we mode
       mode # $+(+,$str(o,$numtok(%os,32))) %os 
;safety clear as mIRC is sometimes too slow
      %os = "" 
    }
;loop some more
    inc %i
  }
;if any left or never hit max
  if (%os) {
;mode names
     mode # $+(+,$str(o,$numtok(%os,32))) %os 
  }