hi! rather than telling you how you could complete your task in a better way, here is why your substitution doesn't work: the search pattern (substr($ordered[$x],3,3)) is not evaluated as an expression, only $ordered[$x] gets evaluated to its value. so you are trying to substitute a string like "(substr(1243234123411224,3,3))" that $ordered[$x] doesn't contain. to illustrate what happens:

my $foo = "12342343432424232";
my $bar = "substr12342343432424232,3,3";

$foo =~ s/(substr($foo,3,3))/fnord/;
$bar =~ s/(substr($foo,3,3))/fnord/;

print "foo: $foo\n";
print "bar: $bar\n";
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the code above prints:

foo: 12342343432424232
bar: fnord
[download]

yt, snowcrash