There has to be some interaction. Without it, it would not be able find DOSBox. About the only thing that ends up in the registry from DOSBox is from the MRU cache or other things from usage (searches, opened in other programs, etc.) Even the official DOSBox installer does not track anything in the Registry. Without interaction the only way to automatically get the location of the user's DOSBox would be to do a file search on the whole system. Besides the time that that would take, if the user had more than one build of DOSBox on their system, the run utility would not know which one to use. A straight forward search would probably just take the first one it found and then quit.
That said, I suppose that it would be possible to do a new version that could refer to an ini or XML file or a registry entry to use some predetermined DOSBox. It could even include DOSBox in the same folder, but that would mean a separate DOSBox for each game. Perhaps just a separate script to be used in batch processing?
I wish my C++ skills were something more than nonexistant. I would love to take on Companion and/or Studio to update/modernize the interface. I would add some of the various tools and utilities, including seamlessly integrate the run utility and my other project.