It would be handy, though, if a sub-directory could be placed in the DOSBox install directory that would show up as part of Z. Yes, it's easy to do something like I did and just put the files on a mounted drive or sub-directory of one. For example, my DOSBox always mounts the C: drive (to C:\Games\DOSBox,) and always sets the path to include C:\DOS (on the mounted C drive.) That way, anything I want to always be available I can just throw into the C:\Games\DOSBox\DOS directory and there ya go.
However, if I'm running many different configs that mount C onto different locations, I then have to copy the DOS directory to all those different locations. If there was just a sub-directory in the main DOSBox directory names "Z" for example, and I could throw common utilities (d.com, list.com, pause.exe, etc....) into there, it would be a lot easier. Just a thought.
I have to admit, though, that I have no idea how hard/easy that would be.