As usual thanks for all replies...
Unfortunately, it does not seem to work with me (!)
Klicking on the file just opens BiaB (clear, since I have defined this type of file to be opened by BiaB) and I dont see any other possibility to uncompress it, I do not even find an unzip Program on my (new-Win10) computer.
Never mind, I still have fun with BiaB 2020.
Bernard