Start Calculate from grub legacy

Hi, I would like to start CLDG 12 from grub legacy (MBR) of other distro.
I generally use:

but I can not find the "core.img." Thank you and congratulations for making friendly Gentoo.

Something like this:

title Calculate Linux
root (hd0,2)
kernel /boot/vmlinuz-3.5.3-i686-CLDX root=/dev/sda3
initrd /boot/initramfs-3.5.3-i686-CLDX

Solved as you suggested.

title Calculate 12, Linux 3.5.3-x86_64-CLDG (on /dev/sdb6)
root (hd0,5)
kernel /boot/vmlinuz-3.5.3-x86_64-CLDG root=/dev/sdb6
initrd /boot/initramfs-3.5.3-x86_64-CLDG