Need help setting up (routing for) a DMZ with UTM9

Hi all,

I am currently in ther process of creating a DMZ on a ESX host to host a game server with UTM 9. 

Here are a few keypoints:

> The External NIC shoul route all traffic coming from the internet into the DMZ.

> The modem I use is ISP managed and allows for me to set an IP address as DMZ address, which I decided to be 192.168.0.2 (all traffic reaching the public IP will be forwarded to it, with exception of a few ports).

> I added 3 NICs. One for managing the firewall from LAN, one External and one for the DMZ (see network diagram below).

> I am able to ping a resource in the internet (8.8.8.8) from the firewall.

>I tried multiple attempts to get the routing working using Static Routing. Unfortunately none of them worked and I started  to question my sanity.

> Network diagram:

Could someone please help me getting the routing to work?

Thank you so much!