while ($time > 0) {
  print " " . ' ' x (3 - length($time)) . "$time $line";
  foreach (1..$backcount){print "\b"}
  $time -= 1;
  sleep 1;
}

##</code><code>##

while ($time--) {
  printf(" %3s %s", $time, $line);

  print "\b" for (1..$backcount);
  # or this could even be written as:
  # print "\b" x $backcount;

  sleep 1;
}