I would probably use two nested FOR EACH .. IN loops
(one to iterate over the list of your three data paths, one to iterate over the FILELIST('*.xlsx'), which has not so many issues as the star symbold wildcard in the FROM statement).
There is a code sample in the HELP for FOR EACH .. IN how to get the syntax.
Within the loops, you can also set variables for the POS_FILE_DATE and POS_TYPE which you can then use in the LOAD statement, so I think you can essentially burn it down to two nested FOR EACH .. IN loops and a single LOAD statement.