Two audio interfaces but different uses in one system

Hi,

I have already got an audio interface for recording and run smoothly.

Recently I get another audio interface (M-Audio Firewire 410). I want to add it to my system as a standalone mixer in which the outputs will be connected to 2 another active monitors, the inputs of this "mixer" are connected to audio outputs of a DVD player.

So, I can control the DVD volume by the knob on the Firewire 410 and by the M-Audio software in my Mac but my original audio set up doesn't change.

I mean, the DVD audio signal pass to the Firewire 410 then output to the newly added monitors only,my original monitors will not be affected (no DVD sound).

At the same, if I play mp3 in i-tunes, the music will output to my original monitors only.

Just like two independent audio set up in one system, is it possible ?

Thanks for any help in advance.

Cheers,

edtayin