You can probably delete it from the terminal. Open one and type the following:
You should see the file listed here. Note the full name with its extension. e.g., 77B72200.xls or 77B72200.xlsx or something. Make sure you only reference this file in the following. Now type:
rm -rf 77B72200.xls
Or whatever the file name is.
If that fails because, "permission denied," do:
sudo rm -rf 77B72200.xls
It'll ask for your password, so type that in.
I think people blow the terminal and sudo'ing little tasks way out of proportion around here, but for the record: Please make sure you really want to get rid of this file, and that you are only rm -rf'ing the file you want to get rid of. Removing something this way is for the most part not recoverable. The file doesn't go to the trash, it just goes away.