I couldn't find any reference to the publish dwf filename options for batch files. I see that you can individually rename the files, but I don't think that helps.
You may be able to create a Custom Task in the Task Scheduler with more control over the naming convention. The below blog post discusses using the custom task more in-depth with an ilogic rule.
http://beinginventive.typepad.com/being-inventive/2011/11/how-to-create-a-custom-task-in-task-schedu...
You may check out the below forum posting to get a start on the ilogic (dwf publishing) code. With a little tweak to the file-name portion of the code you should be able to get what you want.
http://forums.augi.com/showthread.php?139007-iLogic-DWF-Export-Problem
Thanks,
Nathan Chandler
Principal Specialist