This works only with grub4dos versiom later than 4.4 as with 4.4 it was not supporting booting to MS-DOS 6.22.
I was using grub4dos-0.4.6a-2014-01-17.7z
I have to physical drives: compact flash with two partitions and mechanical hard drive with two partitions.
Compact flash partition one (hd0,0) has Windows 98 installed.
Mechanical drive partition one (hd1,0) has DOS and Windows 3.11 installed ( it had also 98 previously, not used anymore ).
By default it boots to Windows 98, but I want to have option to boot directly to DOS 6.22 on this other physical drive.
So, my grub4dos menu.lst looks like that:
color blue/green yellow/red white/magenta white/magenta
title Windows 98
title DOS 6.22
map (hd0,0) (hd1,0)
map (hd1,0) (hd0,0)
title Floppy (fd0)
title Back to dos