If you have barriers to modifying scripts ABCD to control where they save their outputs, why not just let them do what they do, and use FIle::Copy (a core module, included with every perl installation) to move() all those data files wherever you want them to be?

(I'm assuming that if there's any danger of file name collisions, you'll be watching out for that, and renaming files as needed when pooling them together into one place -- that might be another reason to take this particular approach.)