I assume that this is an encoding problem. I would save the Excel file again in Excel on the Mac. Or – also a good “washing machine” – for Office files is the free Libre Office.
This problem seems to be a notorious one.
I searched around and found some threads, that all go by the status Not answered.
The most recent one I am aware of is:
zeRafio Apr 18, 2016
My suggestion for a GREP Search/Replace:
Some older threads here:
Hope, that helps…