I think it will be far easier to port the C code to Perl 5 than to start out with the Perl 6 code and port it to Perl 5.

But in both cases, you will have to understand the original code.

So, maybe, again, now is a good time to tell us where exactly you are having problems with translating the code? This website is not a code writing service and we expect you to spend some effort on the problem and your implementation.