first of all cheers for this community and for the tools made by Luigi Auriemma!
First time posting here. I know that this is a long shot, but I would like to ask for support in order to understand how to unpack a particular .DAT archive from a pretty old soccer game made by Konami (KCET) for the Playstation 2 in 2001 called: Winning Eleven 5. With the help of filecutter.bms I could attach in this very post a .zip folder with a sample of the archive.
Basically inside this big .DAT file I'm pretty sure there are all of the graphics, sounds and whatever concerning the game, in fact all of the other files inside the game image are really small .IRX files, while the whole WE5.DAT is more than 400mb (this one is an early CD based game for the system).
Any help or hint would be greatly appreciated, before posting here I searched for weeks without a clue

All the best,
Matteo