There are a number of differences between Office for Mac and Office for Windows and it's clear you've bumped into one of them.
Here's a thought but I don't know if it will work The free office package Open Office (there's find Mac implementation of it called NeoOffice) will read and write Excel spreadsheets. Maybe if you create a spreadsheet in NeoOffice you can load the spreadsheet into and save it as an Excel file.
Alternatively, but far less conveniently, you could use Virtual Box to create a virtual machine, install Windows on the virtual machine and then install Office in the virtual Windows. I have done this in the past and I know that it works. It's a little more convenient than using Boot Camp to run Windows, because the virtual machine doesn't require you to close down OS X, so you can have the Windows and OS X running side by side on the same machine.
Bob