Basically it should work with the following:
1. create a list files Task identifying and listing your files
2. create a Read node Task, use the following value for the file: {LOOP(CurrentValueX)}
3. create a loop on that Task and use this in the
for each: {TASK(PrevTask,StdOut)}
Then you need to create the XPATH query. I suggest you test this with an existing file first.