Title: Get system decimal separator
Use GetLocaleInfo function with LOCALE_SDECIMAL parameter.
procedure TForm1.Button1Click(Sender: TObject);
var
MyDecimal: PChar;
begin
MyDecimal:=StrAlloc(10);
GetLocaleInfo(
LOCALE_SYSTEM_DEFAULT,
LOCALE_SDECIMAL,
MyDecimal,
10);
Label1.Caption:='System decimal is - "'+MyDecimal+'"';
end;