... Load Particles in RealFlow?

To do this you need a “Binary Loader”. This node type does not create and emit a single particle, and its only purpose is to load already existing (= cached) BIN file sequences:

Binary Loader node > Node Params > Binary Loader > BIN sequence

Once the particles have been loaded, you can decide what to do with them. By default, the particles are loaded and displayed in RealFlow's viewport. There, they can influence other SPH fluid emitters, active rigid bodies, and soft bodies. But, other nodes will not be able to change the Cinema 4D particles' behaviour.