@Data,
I believe that by default, DOSBox should mount C-Drive and show C prompt when started, and for more advance users make that editable in config file.
Something like some other downloading software can do. They create folder for downloads, but you can edit location if needed.
@Shrek,
use DFend. It's nice DOSBox front end.
@Data again.
I think that they might consider to combine DFend with DOSBox. Its GUI interface is nice, and for seasoned users, there is still way to start vanila DOSBox.