My Own Reply....
I have reviewed the Distributed Pro Batch tool and do not see any way that I can run this from a list of p/n I have identified in a flat file without actually exporting all the files to a folder.
I looked at possibly creating a script and modifying the saved .dxc (saved pro batch command) file by adding the file name to the "Object Context=" line but it requires the full path and the version, info I do not have readily available.
Example of line in .dxc:
<Object Context="PDM Test">wtpub://MYWindchill/Products/PDM Test/mypart.prt|v=A.0</Object>
I am abandoning this approach and will create a script that reads the flat file of parts and create trail file on the fly that creates the step file.
Still welcoming any ideas, I was also thinking of using the CAD Publisher and ask for inputs from anyone that has successfully done it this way.