Target New c3D Mocap to exsting Optical Data

I am in a rush to find a quick solution that seems like it should be pretty easy. I have imported a c3d Tpose for a character in Motionbuilder. Now I want to apply that existing optical data to the new c3d mocap file. eg. I want the points to line up with the new data (as it is the same actor). Any help I can get on this would be great. I am completely new to this and am just trying to figure it all out. I am using the latest version of motionbuiler.