Grub Install on existing Partitioned Harddrive

[Sebastian H. Schmidt]

Hello,

I want to install FC 8 on my Macbook Pro (SantaRosa) which is already 
partitioned, and i`m not able to change it. Currently the existing 
Partition Table Looks like this

[EFI][MAC-OS]{Free128MB}[MAC-Data]{Free128MB}[WINXP]

Since there is not enough space left on the harddrive i have to install 
the Linux on a external drive, but thx to Apple it could not boot 
completely  from my external HD, so i had to put my /boot partition in 
one of the Free 128 MB blocks. .. and thats where it gets messy.
Since this new Partition is not one of the first Four FC6/CentOS are 
telling me that this installation is not possible. So 2 Weeks ago i 
installed Ubuntu and it worked fine, i think because it installed the 
GRUB bootloader into the MBR of the Windows Partition (because it 
appears when i wanted to start it).
Now i have to install  FC8x64 and doing that  from the Live CD It 
creates all the directories and necessary  filemounts, but it seems that 
it installed the bootloader somwhere it does not get recognised. And now 
to the question, how do i install the the bootloader into the MBR of the 
Windowspartition but refering to the grub files in the /boot partition. 
Is this possible, does this might work ? ... if so .. how.
I had a look at the grub installation page but it is not clear for me 
how this might work without crashing the whole machine.


grub-install --root-directory=/boot /dev/hda

does [--root-directory=/boot] means "you find your grub data in /boot" ?
does [/dev/hda] means "install the bootloader to /dev/hda" ?
does it might work if i use
grub-install --root-directory=/boot /dev/sda4 ?
because the windows partition is sda4 and i want the bootloader 
installed there ?


thx very,very much for your help.


Sebastian