I live in South Africa and use the English (South Africa) locale on Windows, but make some changes. Rather than the official decimal separator (comma), thousands separator (space) and list separator (semi-colon) I prefer to use the US standard of period, comma and comma respectively. I have configured my Windows regional settings accordingly and virtually every app I use honours this, but LibreOffice however does not, requiring me to enter the decimal comma.
What do I need to do to ensure that LibreOffice, and particularly Calc, uses the English (South Africa) language for spell checking but the US standards for decimal point, thousands separator and list separator?