$test = "\n\n\n\n\n"; The code prints a string of 10s, indicating that the 13/10 combination in Windows has been translated to a bare 10.

That's because, even in Windows, \n only represents LF, not CRLF (that'd be \r\n)*. You can verify this using Dump from Devel::Peek, it'll show you exactly what Perl is storing internally. The only place where Perl on Windows does automatic translation between CRLF/LF is on I/O from/to a file, because there, the :crlf layer is enabled by default (unless you specify the :raw layer or use binmode). So perhaps if you're reading from a file that has CRLF endings, you might want to turn off that layer.

By the way, you might want to have a look at RPerl, it can take a subset of Perl and compile it.

* Update: As Athanasius points out, see Newlines in perlport for even more details.