I was recording in Logic a session of a trio I play in, using the BPFS mics and lines inputs coupled with an ADAT 8 pres unit. I play guitar in the trio, and I wanted to record the guitar into input 3 and 4, blending both its internal pickup ( going into input 3 ) and a Rode NT5 mic to add more of its natural sound ( going into an external preamp into input 4 ). So far, so good.

But then, I also needed to be amplified to match the volume of the 2 other instruments when we play. The obvious solution was to use one of the XLR outputs of the BPFS—which we didn't need—going into a Bose S1 I have. But I just couldn't find a way to have ONLY either the pickup or the mic input of my guitar coming out of the BFPS output. I tried everything I could think of, but all inputs/tracks kept coming out of it. 

I understand that it is normal that all inputs of the BPFS are coming out of the outputs, but there must be a way in TotalMix to ouput a SINGLE input, in this case my guitar input. Since there are "submixes" that can be created in TotalMix, I take it that it must possible. Or there's an even better, simpler way to do that.

Any help would be appreciated. I have to find a way to do this, for that trio and other projects. Thanks.   

PS: I'm a fairly new user of RMEs, and definitely limited in my understanding of how TotalMix works.