[André Otto]

Just in case if someone has the same problem, here is what solved my problem very simple:

txt = text.sourceText;

txt.replace(/”/,”„”).replace(/”/,”“”).replace(/”/,”„”).replace(/”/,”“”).replace(/’/,”’”).replace(/’/,”’”).replace(/ß/,”ẞ”).replace(/ß/,”ẞ”).replace(/ß/,”ẞ”).replace(/ß/,”ẞ”)

The expression replaces the wrong signs in the written order: two times for quotation marks followed by two apostrophes and four capital letter ß (what’s very common in German).

Thats all I have to expect in my case so it will work fine hopefully.