Just to make sure I understand: the filenames include all the relevant
information you need to use? If that is in fact the case, one way to
collect information from the existing files is to open a DOS window
and type

dir c:\your directory tree here\*.xls c:\your directory tree here
\POFiles.txt

This will create a text file that contains all the xls files in that
directory. You can then import that text file into excel, and parse
the data into a useable format.

This method requires that you type everything exactly, know where all
the directories are, and know a few things about DOS. It's not user
friendly- that's why Windows was developed- but it will work.

Moving forward you can set up your template to save important PO
information from each file to an archive file.