Who needs list separators? You do, trust me. You should consider list separators whenever you handle a string array in multi-column list boxes, memory, or comma separated values files (.csv).
.Csv files are only comma separated for languages that use a comma as list separator. However, many languages do use a comma to separate decimals in numbers, that's why they use e.g. a semi-colon (;) to separate string arrays.
Get the list separator setting of the user system. The Windows API provides functions to get the appropriate values. In .Net, check the culture name space.