Insert the link to the file from which you want to retrieve the source code into 'file_path'.
Insert the link where you want to receive the decrypted file into 'file_output_path'.
Insert the KEY into 'old_string'.
The location of the KEY is shown in the example: Set key=650hFGKcaelOPBjqkWTtdXRyUDHsvrfA9MuYQ8x1pzLIw2g4EnmCbZ3JNVi7oS
Then 'old_string' will look like this: old_string = r'%key:'
Next, remove everything from the batch file, leaving only what was after the '=' sign in the key (refer to example.txt) and the encrypted code of the program itself.
P.S., you don't need to remove the 'cls' command.
P.S.S., this programm doesn't give you exact code that was written, but only gives you general information about what a particular script does