NPF and port forwarding?

[Mirko Thiesen <thiesi%gmail.com@localhost>]

I've been trying for quite some time now to get port forwarding
working with NPF - but to no avail.

I have a system with several NICs, all of which are directly connected
to the Internet and each with its own IPv4 address, so I don't need
any NAT. What I do want though is connections hitting a particular NIC
at port x to be forwarded to port y on the same NIC.

Would someone be so kind as to tell me what exactly I have to put in
my npf.conf to achieve this? I don't seem to have any luck with any of
the examples in the documentation.

Thanks in advance.