#excel to #csv in #powershell (New-Object -ComObject Excel.Application).Workbooks.Open("c:x.xlsx").SaveAs("c:x.csv",6)
— laurentsch (@laurentsch) February 13, 2015
One-liner to convert Excel to CSV (or to and from any other format).
There is a bug 320369 if you have excel in English and your locale is not America. Just change your settings to us_en before conversion.