You can choose how the number is formatted. All the apps that add the decimal and thousand separators will do it the way you instruct the machine to. On that menu you shared.
You can actually re-map some of your keyboard through your system settings under accessibility. You can also use apps like karabiner, to do a full remapping of it..
Also remember that you can choose between keyboard layouts, and switch on the fly, for that I also recommend a keyboard cover like the ones KB covers makes, if you require the visual cue.. I need one to start learning Dvorak layout!
Cheers