I would think a .bat file would launch the game also, but have you tried the .exe file? I'm not familiar with what you're working on exactly, though I began my computer days on DOS. but I do know generally, a .exe file is what you want to use to open up an application.
If nothing else, not trying to send you away or anything, but try asking people on the forums of the DOSbox app on troubleshooting or how to use the app.