my $line = 'Text with unusual punctuation<91><91><91>  I<92>m not going to lie<93> this is odd text<94>';

$line =~ s/<91>/./g;
$line =~ s/<92>/'/g;
$line =~ s/<93>/,/g;
$line =~ s/<94>/!/g;
# etc.

##</code><code>##

my $source = 'my_filename.txt';
my $target = 'new_filename.txt'; #THIS FILE WILL BE OVERWRITTEN

open SOURCE, "<$source" or die "Can't open $source. $!\n";
@array = <SOURCE>;
close SOURCE;

s/<91>/./g for @array;
s/<92>/'/g for @array;
s/<93>/,/g for @array;
s/<94>/!/g for @array;

open TARGET, ">$target" or die "Can't open $target. $!\n";
print TARGET @array;
close TARGET;