You might start by reading your perl compiler docs they should tell you where files are extracted to and how to access them. I ASSUME that you're using the DLLs due to a requirement by a module you're using. If so you could place a BEGIN{} block at the top of the script to ensure your PATH changes are done before the modules are used. Modifying the path variable should be as easy as $ENV{'PATH'} .= ';C:\Path\to\directory'; Note I'm including the preceding semi-colon in my path string - and the .= appends my string to the end of the existing PATH value. But I'm just flying from the seat of my pants here. Check the wonderfully useful perldoc website and search for %ENV for how to access/modify environment variables.