Like I mentioned in my other post, I use the "Import Products (older version)" to bring items into EZP. Along with that, I use "Export List" to export items from EZP - it creates a .txt file that I can then open it with Excel. It results in a single page that can be manipulated the same way as anything else in Excel.
I'm not necessarily recommending it for you (as Ronald mentioned, you can really mess up your Product list in EZP if you import from Excel and don't do it right), but it works well for me.
As a precaution, I always try to make sure to import a file in my back office version of EZP first (before importing it to the "live" version) to see if it messes up anything. As an example, if you're just one character off on something like a Category, you'll suddenly find a new Category in addition to the old one. Or you can suddenly double your inventory.
