In the nicest possible way, it seems you're getting a bit X-Y in that you're trying to fix the wrapper code around the actual code. If all you need to do is transform the file, then you don't actually need perl or a perl module at all.

If I were you, I'd, download the MSXML application and get transforming on the command line.

msxsl C:/filename.xml C:/filename.xsl -o C:/output.csv
[download]

is all you're really trying to do.

And if you really want to do it from perl, you can always do system or backticks or whatever around that, creating your own wrapper.

It sucks, but hell, you're stuck transforming XML on Windows (as am I, can you tell?) you might as well bite the bullet.

Let me know if I can help.