Here it is customized for your case.
Action:
action uses wow64 redirection false
parameter "output_folder"="{parent folder of parent folder of client folder of site "actionsite"}\filescans"
parameter "output"="{parameter "output_folder"}\pst-scan.txt"
folder create "{parameter "output_folder"}"
delete "{parameter "output"}"
delete __appendfile
appendfile dir /s /b c:\users\*.pst > "{parameter "output"}"
delete run_scan.cmd
move __appendfile run_scan.cmd
waithidden cmd.exe /c run_scan.cmd
This saves a listing at “BES Client\filescans\pst-scan.txt”. The content of that file will look like
C:\Program Files (x86)\BigFix Enterprise\BES Client\filescans>type pst-scan.txt
c:\users\jason.walker\AppData\Local\test1.pst
c:\users\jason.walker\AppData\Roaming\test2.pst
Now you can use an Analysis to retrieve the resulting paths and file sizes:
q: (pathname of it, size of it) of files (lines of files (pathname of parent folder of parent folder of client folder of site "actionsite" & "\filescans\pst-scan.txt") as trimmed string)
A: c:\users\jason.walker\AppData\Local\test1.pst, 7
A: c:\users\jason.walker\AppData\Roaming\test2.pst, 7