One of my colleagues went to visit a placement student in London. He found that the most useful thing that the student had learned on their mathematics degree was a familiarity with the spreadsheet package Excel. I had the same experience.
We do teach some Excel to the students, but because the staff don't like to use it, apart from entering marks, we don't perhaps teach as much as we should. Excel is really rubbish at plotting histograms, so that biases me against it. Also a useful data analysis package only existed for Windows.
My colleagues suggested that we look into getting the students to take some exam to get Excel certification. Now that I have done a quick web search, I see that Microsoft actually off a number of certification exams. I have seen a University in the USA off certification in the SAS statistical language, but we don't use it because it is expensive. It is not clear to me that a University department should be also be certifying students in Excel. It might be hard to organize. It is not clear how to pay for the student's exam. Also the exams are taken at special places.