Monitor posts in facebook group by screenshots

We want a tool that will take screenshots off all photos uploaded on our Student bike sale group. The idea is to become able to filter out sellers in this way. 1) The screenshots must be saved in the following format: [Facebook name] [date placed: yyyy-mm-dd] [photo number].png - [Facebook name] is simply the facebook name of the uploader. In the example photo this will be Aliakbar Norozi - [date placed: yyyy-mm-dd] will be 2017-09-09 in this example - this uploader has in total 6 photos so the photos must be numbered 1, 2, 3, 4, 5, 6 2) The tool should somehow be able to take screenshots of the new photos only! So if we run the tool on daily basis for example, it should only take screenshots of the newly uploaded ones. 3) I would like to be able to change the save location. This doesnt need to be from a fancy GUI. It can just be by changing the code itself. There are many possibilities and languages to implement this program. Some webscripting or webprogramming will be needed to extract the name and date. For the rest its a really straightforward program. The budget for the tool is very limited, so I really need someone who can fix this easily because he already has experience with something similar.