I think this should work. Didn't test it though.
@echo off
if exist combined.list del combined.list
for %%A in (*.list) do (
call ParseCSV.bat "/i:|" "/o:|" <"%%~A" >"%%~A.tmp"
for /F "usebackq tokens=3,4,6 delims=|" %%G in ("%%~A.tmp") do >>combined.list echo %%~G^|%%~H^|%%~I
del "%%~A.tmp"
)