Hoping someone can help me with a bit of a routing query with the RME mixer.

A brief bit of background:
I always monitor through the SPDIF outs of my Multiface II but am frequently changing other routings, switching between sending a copy of the DAW output channels to SPDIF out, or sending the analog ins to SPDIF out, depending on whether I'm patching in outboard FX, but either way, anything I can hear at the speakers is always coming from the SPDIF outs. When I put headphones on, I just want to hear exactly what's going to the speakers.

So what I'd like to do is have the phones output mix always automatically match the SPDIF output, i.e. make it so that whatever audio is present at the SPDIF outs should also be sent to phones. Can this be achieved through any clever routing/loopback?

Thanks
Gabe