A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
Two key points :-)
- Export is just another name for Save As - the process is the same regardless of name, &
- File management on OS X is [pretty much] dictated by Apple
If you're using a newer version of OS X (10.8 or Later) you might see if the Duplicate command is available from the File menu. It may be an acceptable alternative.
Another option similar to what Bob G suggested;
- Right-click the sheet tab
- Choose Move or Copy
- Select (new book) from the To book dropdown
- Check Create a copy
- Click Close
- Enter a name for the new file
- Choose the preferred Format
- Click Save
You'll be left working in the original file.