Batch file that plays same trail file on multiple parts

[infinitevox]

Hi!
I registered here to ask this question. I've been working on it off and on for a week and can't quite figure out where I'm going wrong.

I'm going to have about 100 parts coming through that I need to populate parameters for (and a couple other tasks).
So I recorded a trail file that will do the tasks. I tested it independently and it works no problem.

I then wrote a batch file that will go through the directory I give it (where the parts are located), it will export the list of parts to a text file.
Using this list, I set up a FOR loop to replace the part number in the trail file at each iteration.

The problem I'm running into is this:
When the batch file directs Creo to open a file, I get this message:

Cannot find C:\Users\uh345d\Desktop\AutoCreo\Backup\PA.txa C:\Users\uh345d\Desktop\AutoCreo\Backup\Test_Folder\%%a

Basically, Creo is trying to open that as a single file, instead of opening %%a (Part from list) and running PA.txa (Trail File)
I tried inserting pro_wait as well, as it was a separate command I ran across that may or may not help

Here is my code:

Spoiler

@ECHO OFF
ECHO Brought to you by: ME
:: Prompts user for the directory
set /p pathName=Enter the File Path of the folder:
set /p username=Enter your username:

:: 1. Change to the location set above
:: 2. List all files in that directory and store in a text file on desktop
cd %pathName%
dir /s /b *.* > c:\users\%username%\desktop\list.txt

:: 3. Opens Creo then runs 'for loop' to run script against each file in list.txt
:: This sets and populate parameters
:: 4. Add -g:no_graphics to run in non windows mode
for /f "delims=" %%a in (c:\users\%username%\desktop\list.txt) do ("c:\Program Files\PTC\Creo 2.0\Parametric\bin\parametric.bat" pro_wait "C:\Users\%username%\Desktop\PA.txa %%a")

Pause

Any help would really be appreciated.