how to route behind a nat interface ?

[RJ45 <rj45_(_at_)_slacknet_(_dot_)_com>]

Hello,
I have a OpenBSD nat with 2 interfaces.

fxp0 192.x.y.z
fxp1 172.16.0.254,
     172.16.1.254,
     172.16.11.254,
     172.16.250.254,
     172.16.254.254,
     172.16.253.254

fxp0 is the nat interface and here is my configuration:
nat on fxp0 inet from 172.16.0.0/24 to ! 172.16.0.0/24 -> 192.x.y.z
nat on fxp0 inet from 172.16.1.0/24 to ! 172.16.1.0/24 -> 192.x.y.z
nat on fxp0 inet from 172.16.11.0/24 to ! 172.16.11.0/24 -> 192.x.y.z
nat on fxp0 inet from 172.16.250.0/24 to ! 172.16.250.0/24 -> 192.x.y.z
nat on fxp0 inet from 172.16.254.0/24 to ! 172.16.254.0/24 -> 192.x.y.z
nat on fxp0 inet from 172.16.253.0/24 to ! 172.16.253.0/24 -> 192.x.y.z

everything works in nat but I Want people which are on subnet
172.16.0.0/24 to being able to connect to hosts on subnet 172.16.11.0/24
on the internal network for example using 172.16.1.254 as the gateway.
This does not work automatically.
How can I do that ?
do I have to write a rdr rule ??

thank you

Rick