Installing Debian using custom kernel

[Tushar Joshi <tjoshi@lonix.org.uk>]

I've just bought a new Dell R410 and it seems the Broadcom ethernet and
the H700 raid card aren't supported with Lenny's CD netinst. I've
created a custom kernel but I wonder if anyone has any pointers on how
to create an initrd image for this and put this on a netinst CD. I've
used simple-cdd to create a boot CD but that didn't seem to work and
still used a standard kernel. Everything else I've earched for on the
web talks about creating floppy disks. Any help would be greatly
appreciated, 

Thanks

Tushar