"The problem is that I'm not exactly sure how that works."

As someone once said, "ignorance can be cured." In fact, that's one of the Monastery's missions. You can read all about "how (Spreadsheet::Read) works"

You may also wish to familiarize yourself with the local guidelines -- see On asking for help and How do I post a question effectively?.

...and, just BTW, it may be worth considering Spreadsheet-ParseExcel.