Jochem:
I don't know where I got my version of Dune from, but it includes a .bat file containing the following:
@echo off
logo
duneprg ENG VGA SDB2222 HIM 386
To create a setup in Dosbox, I use D-Fend:
http://members.home.nl/mabus/dfend.htm
No need to type any commands, just click and pick your choice.
So I run D-Fend as a front end to Dosbox, and I run the dune.bat file I mentioned above.
Hope this works for you.