If you are required to use the radio, you need a LPE on your licence. See FCL.055 for the specifics. This also states:
...in either English or the language used for
radio communications involved in the flight.
So the question is whether you can do a LPE in English and/or Spanish (skipping the German one) on an Austrian PPL. As Jan said, best to ask the Austrian CAA, or go and have a chat with one of these authorised external examiners. They will know.