[Fizzlemizz]

If you set up default text strings with your messages, either stand-alone or in a table, then when the game loads you can then detect the localisation and overwrite the variables with the locale specific messages.

local MyMessages = {
    Winning = "WINNING!!!",
    Losing = "LOSING!!!!",
}

if GetLocale() == "deDE" then
    MyMessages = {
        Winning = "GEREINNT!!!",
        Losing = "VERLIENREN!!!!",
    }
end

-- Pardon my german, it is coutesy of google tranlate.

Everywhere xx:SetText(MyMessages.Winning)
You will get the current locale message.

There may well be other, better ways.