my @headerArray = "a,b,c,d,e,f,g,h,i,j,k";
my $headerArrayRef = \@headerArray;

...

my $headingAref = "$headerArrayRef";

...

    my @headerArrayCopy = @$headingAref;
    print ($file "@headerArrayCopy\n"); #adds header
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@headerArray starts out as a single string (an array of one element).

You then assign a reference of that array to $headerArrayRef, which could have been done in one step like this:

my $headerArrayRef = [ "a,b,c,d,e,f,g,h,i,j,k" ];
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Next you convert that reference to a string and assign it to $headingAref. Which means that $headingAref can never access the original data from @headerArray.

And finally you dereference a string which is an error and will not work.

    for ($currentIndex >= $readLineFrom and $currentIndex <= $readLine
+To){
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In Perl a for (foreach) loop iterates over a list but that is a list of one value (whatever $currentIndex >= $readLineFrom and $currentIndex <= $readLineTo evaluates to).

It looks like that should be if instead of for:

    if ($currentIndex >= $readLineFrom and $currentIndex <= $readLineT
+o){
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Or you could do it the "Perl" way:

    if ( $readLineFrom .. $readLineTo ) {
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