One way to do it:
Give each object the start/end locations and its own curve. Then use a global time-elapsed to drive them all. When they spawn they get added to the list. Then, on tick (or timer), go through the list and tick each one. The alpha will be the same for all of them but each will be able to follow their own curve between their own start/end points.
That would be a more dynamic way to do it. But the simplest way is to use multiple tracks in a single timeline to drive all the objects. If you know you will have a (low) fixed number of objects, this might be the easier way to go.