A. Set Window's regional settings to some, where semicolon is a list separator (German, Estonian, etc.). (Maybe it will work also, when you set the list separator for your current regional settings to semicolon.) Open your workbook, be sure that the worksheet you want to convert is only one in workbook or at least the first one. Save AS CSV (Comma Delimited).

B. This works when you don't have any commas in your current entries. Open your workbook, be sure that the worksheet you want to convert is only one in workbook or at least the first one. Save AS CSV (Comma Delimited) and close the csv-file. Open the csv-file with notepad, and replace all commas with semicolons. Save.