Updating currently developing FusedPointCloud map with previously saved object pointcloud


I have segmented object point clouds from a previous point cloud mapping run and I would like to display them on the currently developing 3D FusedPointCloud map.
I am using the area mapping functionality of the ZED2 camera, I just can’t figure out how to add a previously saved point cloud [x y z rgba] data to the FPC so that I can see the previously detected objects on the current run.

Could anyone please provide any help?

Thank you