Hello ! Considering the way special characters are processed in different countries has everything to do with their statistical measures .Basically, one does not have any advantage over the other ,its just the set of quality standards they tend to follow . For example, many of US based companies suggest while writing your name in the Resume,you must make sure its centered aligned but those in Europe suggest it should be aligned to the left .So its completely based on your quality standards.To cure this problem I could suggest a few measures :
1)When converting btc make sure you've choose France as your country (if you've set your google to its default location then dont worry it should do it for you)
2)Try to use as many web sites based in France because they'd follow the same set of standards
3)Manually just replace the comma with the dots which I think seems much easier .
