Some people have been having trouble saving their Excel data sheets using the file naming protocol outlined by DEP. If you aren't able to copy and paste the file name generated by the template into the "Save as" box, read on.
When you copy the file name it is automatically saved on the "Clipboard". When you open the clipboard within Excel the filename will be there. All you have to do is click on the filename and then go to Save As and it will paste. I created a super high tech video showing the process: