(racoon 830) Connecting to CheckPoint FW-1 using Racoon

Hi,

I'm a newbie at IPSEC, so I apologise in advance for any silly
statements I may make!

I run a Linux laptop, with kernel 2.6.5 with built-in IPSEC.  The OS has
racoon.  I'm trying to VPN into my office network, which uses a
CheckPoint FW-1 firewall.  (all on IPv4)

Using WinXP, I connect using CheckPoint's SecureRemote, provide my
username and pwd, and I'm in.  (Connecting using IKE encryption)

How can I do the same using Racoon?  I cannot modify the CheckPoint FW-1
settings, so no pre shared keys.  I need to use a username and passwd
(my corporate Windows domain login and pwd) to access the network.  

Most of the example configs I've seen use pre shared keys, or are for
network-to-network VPN tunnels.  I want a simple client-to-server VPN
connection.  Are there any sample configs about that I can refer to?
Has anyone successfully done this before, and have any experiences to
share?  Help very much appreciated!

Thanks,
Manik