If you want to give the user a settings to alter the decimal point then go for it, though it can be made so that they don't need too.
If any user has any more problems with the CSV files then ask them to upload the problem file so you can use it and locate the exact line of code you have that may be causing the problem - easy to do if you set your TinySA-App project into debug mode (menu / view / configuration manager), set a break point on a line of code in the function with the possible problem and then single step through function, when the problem crashes (exception pop-up boxes or whatever) then you've found the line of code that needs fixing.
