DOSBox v0.72 - The Language File

A language file can be generated by CONFIG.COM (CONFIG -writelang langfile).
Read it, and you will hopefully understand how to change it.
Start DOSBox with the -lang switch to use your new language file.
Alternatively, you can setup the filename in the config file in the [dosbox]
section. There's a language= entry that can be changed with the filename.