Got a new Mac and now Excel won't open

Got a new Mac with Maverick OS X 10.9.4 and had to re-install a lot of my software in spite of the data migration from my old hard drive. When I try to open Excel for Mac 2004 (which I HAVE to have because that Apple software Filemaker Pro will only import from an Excel file, not from my Numbers file and how that makes any sense I have no idea), I get an error message saying:

"You can't open the application"Microsoft Excel" because PowerPC applications are no longer supported."

WHAT does this mean and how do I get around it? I don't want to use Excel. I want to use Numbers. And I want to use Filemaker Pro, although why when even Apple isn't interested in it...whine...