txt output file not showing up in Process Monitor

Hello,

I am creating a .txt file in my App Engine program, but I am not able to see the file in the Report/Log Viewer.  I can see the file in the Appserver 'files' folder, but my users won't be able to access the folder everytime it is run. Here is the syntax:

GetFile("my_test.txt", "A", "a", %FilePath_Relative)

If I change to use "W' mode, the file would appear in the Report/Log viewer, but then it shows the lines I wrote from my last step only.  I need it to be in append mode because I am writing this text file in many different AE steps within the program.  I tried with different file extensions (.log, .out) making sure it is matching what the Process Scheduler System Settings but still not working.