I modified Jonesy44\'s for my own use, if you do not mind =)

alias genpass {
  var %c = 1, %rpass
  while (%c <= 8) {
    if ($rand(1,2) = 1) { %rpass = %rpass $+ $rand(a,f) }
    else { %rpass = %rpass $+ $rand(0,9) }
    inc %c 1
  }
  return %rpass
}