Hallo!
There are a few things first. The attached file is just a frontend. I will need file located at \\Server[\c]\Zahn32\Termin32.dat. The program is asking for this file to link to, and that is most likely the backend (database with tables).
Second, since this is a compiled Access file, the coder can only replicate it by making it from the scratch. There is no way to turn this back into a file that can be opened in design mode.
Now, that leads me to the amount of work, it is nowhere near the project budget under 30€.
I am working with MS Access past 25 years and I was Microsoft Access MVP twice. I've learned German in school for 9 years (all grades "A") and I understand a lot, but since I barely used it, I am not perfect, but that will help to understand the interface in case I need to replicate the program.
There are few screenshots on my profile of the programs I made, but on the last question, the timeframe, I cannot answer until I have the database so I can run the program.
And, yes, we are in the same time zone which will make communication easier.
Regards,
Branislav Mihaljev