Code:
alias acomp {
  var %dialog = acomp
  if ($dialog(%dialog)) /dialog -vie %dialog
  else /dialog -md %dialog %dialog
}
dialog acomp {
  title "Auto Complete"
  size -1 -1 90 50
  option dbu
  combo 1, 0 1 65 50, sort size edit
  button "Close", 2, 65 1 25 12, cancel
}

on 1:DIALOG:acomp:INIT:*: {
  var %a = 0
  while (%a < 100) {
    /did $iif(%a == 0, -ca, -a) $dname 1 $+($rand(a,z),$rand(a,z),$rand(a,z),$rand(a,z),$rand(a,z))
    /inc %a
  }
}

on 1:DIALOG:acomp:EDIT:1: {
  var %a = $did(1).lines
  while (%a > 0) {
    if ($did($dname, 1).text iswm $did($dname, 1, %a).Text) {
      /did -c $dname 1 %a
      return
    }
    /dec %a
  }
}


Til its implimented, heres an example. You may have the workaround already, but maybe someone else wants it >:D