For the start I would be happy if Excel would, in the German version, by default start to separate CSV values by comma and not semicolon. This "bug" did cost us alone hundreds of support hours. We fixed it by switching to XLS, but still CSV is out there and causing headaches (Mailjet for example can't create correct CSV files - luckily SQLite can read them).
Microsoft -> The name of the format is 'comma separated values' not 'semicolon separated values'!
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).
Microsoft -> The name of the format is 'comma separated values' not 'semicolon separated values'!