Mixing down 1 track through external effects?

[jlab]

What I want to do is mixing down 1 track a time, channeling them through external effect units without having to worry about latency and problems with synchronizing. Further more I only want to hear the signal after the analog processing and fiddling with the effects, not the track as dirrect output from the computer, but still be able to hear the other tracks.
How can this be done, in the simplest way? and Do I need a hardware mixer incase alternative routings is needed?

My hardware and software is basically a Mac, Logic Express 9, and a M-audio Profire 610 audio interface (8 inputs, 8 outputs)

(+ a Sherman filterbank 2 (analog synth) and a bunch of guitar effect pedals and of cause the necessary preamps, mics e.t.c.)

 

[moresound]

Are you going to use the guitar effect pedals to do this jlab?

 

[jlab]

Yes, I know there is some problems with the input and output level, but I guess I can solve that by adding a preamp, that can adjust the input and output level, that's realy not the big problem here. It's the first part I cant figure out. To get a signal from one track on a multitrack recording through the effect chain, only hearing and recording that output, without hearing the original uneffected signal, and in the same time be able to hear the other tracks and without latency problems.