#!/usr/bin/perl

$upload="<upload dir>";
$output="<output dir>";
$inputFile="$upload/inputFile.txt";

$filename="$upload/file.txt.mrk";
$outFile="$output/test.tmp";

open(MYINPUTFILE, "<$filename"); # open for input
open(MYOUTPUTFILE, ">>$outFile");
my(@lines) = <MYINPUTFILE>;
my($line);
 foreach $line (@lines)
 {
 print $line;
 substr($line,11,13)="  ";
 print MYOUTPUTFILE "$line";
 }
close(MYINPUTFILE);
close(MYOUTPUTFILE);