unattended RIS + partitions

[steo]

hi all,

here is my problem

i have computers with large disks divided in 2 partitions

I'm using RIS under W3K so i made my image from the XP install CD.

I want just to install automatically XP on the first partition without repartioning an reformating all the disk

The second partition is used to store user's backups. I've tried with some commands in my unattended fil (Ristndrd.sif) autorepartition = no, usewholedisk = no, repartition = no ...

but the installation ask me always to chose partition. :/

If i set all commands to yes, it delete all my partitions, make only one big and format all the drive...

anyone know how to not change other partitions than C: and use this one automatically for XP installation ?