I think you might be looking to change STDIN, STDOUT, STDERR so they point to the files you have opened. See How do I dup() a filehandle in Perl?.
Update: Sorry, I didn't actually read the code, just the description. It looks like you've already read about duplicating filehandles.

In reply to Re: how to exec() with my filehandles ! by superfrink
in thread [Resolved] how to exec() with my filehandles ! by snfever

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