DLNA over opnsense?

[brononius]

I've got 2 networks (WAN 192.168.0.0 and DMZ 192.168.1.0).

On the WAN network, I've got my providers modem (192.168.0.1), and my providers digirecorder (192.168.0.2). These devices must be on the same network, for interactive services.
On the DMZ, I've got a mediaserver (192.168.1.2).

From the digirecorder, I would like to allow DLNA towards the mediaserver. But I can't figure out what I should do. The digirecorder can't be configured, this does a discovery on the 'lan' (=WAN).
So I was thinking of 'natting' the mediaserver on the WAN network. But this doesn't seem to work.

Any idea what I should do, and how?