You'll want Daum's SVN version of dosbox, not the latest stable version.
You need to have an MSDOS boot floppy disk image available, that's the boot622.ima file.
You also need to convert your windows 98SE iso file into a hard drive image, and IIRC WinImage is the easiest way to do this.
The commands at the end of dosbox.conf will need to be commented out in order for you to perform the above steps.