IPFW portforwarding / kernel question

[Henk]

Dear FreeBSD addict,

I am running FreeBSD 4.9-RELEASE on a machine with 4 ehternet devices.
192.168.1.1 is connected to my ADSL router. My FreeBSD machine nicely
routs all traffic between the 4 devices.
 rl0 192.168.1.1/24 (WAN-side)
 rl1 10.0.10.1/24 (LAN)
 rl2 10.0.20.1/24 (LAN)
 rl3 10.0.30.1/24 (LAN)

My wish is to forward all incoming tcp traffic that arrives on
192.168.1.1:4265 to 10.0.10.151:4265 in the local network.

Question 1:
Can somebody help me out with the right ipfw command to achieve this (or a
link to where *forwarding* is explained).

Question 2:
Do I need to recompile my kernel with the IPFIREWALL_FORWARD option?

My kernel is compiled with the following options:
 # options for IPFW / NATD
 options         IPFIREWALL
 options         IPFIREWALL_VERBOSE
 options         IPFIREWALL_VERBOSE_LIMIT=10
 options         IPDIVERT