being able select a channel and route it to "send c"-my effects devices, without it playing over the playing clips

i am launching my stems with my set. so say i wanted to select my drums chnnel and ONLY beat repeat those. i want be able to send them to return c/ my fx channel, but since i have the certain stems already sending to A or B, to use in the crossfader, i'm struggling to find a way to send the specific channel to C while being able to mute/turn down the side it is in of the crossfader, so that i can beat repeat just those drums, without the sound beat repeating OVER the drums already playing in either A or B. if you understand this lol, please could someone help me with a solution? thanks. i can screen shot if you want