you can't use vhd command with other GRUB build. You can place the kernel file and initrd on your real hard disk, so you don't have to use vhd commmand.
read this doc:
www.vmlite.com/appliances/ubuntu-1104-readme.html
section 5.2 for more info.
5.2 Configure Legacy GRUB
For GRUB 0.97 and similar, you can add an entry to your GRUB config file, /boot/grub/menu.lst, using any text editor, and insert an entry like the following:
title VBoot - Ubuntu VHD Boot
kernel /boot/ubuntu-1104/vmlinuz-2.6.38-7-generic root=/dev/sda1 vloop=/boot/ubuntu-1104/ubuntu-1104-beta1-i386.vhd vlooppart=p1 quiet splash
initrd /boot/ubuntu-1104/initrd.img-2.6.38-7-generic
quiet
Another simple way is to chain load to VBoot GRUB2.
2.3 Chainloading from other boot loaders
It sIt should be very easy to chainload from other boot loaders.
Chainloading from GRUB2:
menuentry "VBOOT" {
set root='(hd0,1)'
linux16 /vbootldr
}