Catch a file?

Hello, Guys, could you please help me. How do I get a file to manipulate it. Every time I download this file it changes its name. His extension is .zip? For example: if I download it on 08/28/2018, tomorrow will be

it is using system date as part of filename to save it, you can use sysdate when you try to access the filename. i.e, you can dynamically create filename at run time to access the file