http://neosmart.net/forums/showthread.php?t=3596
and the earlier 3 system version it links to might be of some help.
HnS boots multiple XPs straight out of the box from the top menu.
You don't need to edit boot.ini. Each system uses its own boot.ini. (It's only bootmgr that insists on having its own copy of boot.ini with all the XPs inside)
(HnS uses an old version of grub4dos (pre UUID), so its syntax is the legacy (hdx,y) format. I'm not sure how it works with grub2 (or if it does), because my 10.4 Ubu is one that's been updated from 8.04, not installed fresh, and still uses legacy grub)