Select Code to Download

my %exs;
$file[ $_ ] =~ m[\s+EX\s+[^,]+,(\S+)] and push @{ $exs{ $1 } }, $_ for
+ 0 .. $#file;

for my $rtn ( keys %exs ) {
    my $n = 0;
...
    my $subst = $1;
    $file[ $_ ] = "\t$subst" for @{ $exs{ $rtn } };
}