Reading 'Cache on File' node Append problem

[Joung Art]

I am reading a cache with the Cache on File node and want to add the cache to other points generated in the point cloud. It only works with append switched on. But then it creates new points for each frame instead of updating the positions of the points read in the first frame.

How can this be done? I tried generating sample set and reading new positions. I also tried ID to location. each time I can't update the point positions. I only get more points.