Get/Copy current Excel file's path
The Excel function
=CELL("filename",A1)
will give you the complete path to a file that has been saved. You can copy the result of the function and use Paste Values to retain only the text.
If the file has not yet been saved, the function returns a blank.
You can 'option-right click' the file from finder and one option is to copy the file path to clipboard. This at least gives you access to the path.