Yes, I know, but...
if you know, then why are you asking something technically impossible.

GRUB can't boot second OS directly coz Second OS doesn't have necessary config files and you can not create separate boot.ini file for Second OS.
GRUB uses chainloading and it doesn't access boot.ini file directly. GRUB shifts control to Windows Boot Loader via chainloading and Win Boot Loader ( installed in the Boot sector of First Windows OS ) calls boot.ini file.