Just use a decimal point instead. Switching the delimiters depending on locale makes it extremely impractical to use CSV for data interchange with continental European Excel users.

Microsoft Excel is the only program I know that insists on locale-specific interpretations of CSV. To read a standard CSV into Excel in a continental European locale, you need to either switch your locale at the Windows level, or to manually set every delimiter in the Excel text import wizard (requiring multiple mouse clicks for each column).

This can easily be solved in CSV by escaping or quotation.