$pad_char = "0";
$pad_len = "3";
$padded = "";

open IN, '<ConvertMe.txt' or die;
while (<IN>) {
   chomp;
   my($octet1, $octet2, $octet3, $octet4) = split(/./, $_, 4);  

   foreach( $octet1, $octet2, $octet3, $octet4 ) {
     $padded = $pad_char x ( $pad_len - length( $_ ) ) . $_ ;
     substr($converted, legnth($padded ) ) = $padded;
   }
   
   open OUT, '>>Converted.txt' or die;
   print $converted;
}
close OUT;
close IN;