Connect the eight outputs from the soundcard to eight channels of the mixer. In CEP, you have the multitrack view up and looking at your tracks. Rightclick on the track you wish to assign at the extreme left (where the mute, record, solo buttons are) and a window will come up. There's two drop down windows there, one to select a recording source and one to select a destination (which one of your soundcards eight outputs to use). If it's a mono track and you want it to be isolated on its own mixer channel, in CEP you assign it for example to outputs 3/4. You only want it in 3 so you pan it hard left. All this in CEP software. Now it will come up only in channel three on the mixer (assumming that you patched souncard outs one through eight to mixer channels one through eight).