Ok. So, if you want to change the path to something else, then I think you should be using, "<driveAndPreviousFolders>/ppm/filestore" (i.e., the fully qualified path (assuming its Windows) ).
And once you upload a file that is non empty, the App will create "clarity/Files/<3NumbersFromLeft - the millionth number>/00<millionthNumber>/<Yourfile>, in front of it.
Give it a try
Also, give this thread a read, if you haven't already: CA Clarity Tuesday Tip: Attachment Attribute