I'm not completely sure what you are asking, but if you can embed the 3-sphere into a 4D vector space (I can't say if you can always do that or not), then two separate points determine points on a line between them, as that holds in any dimensional vector space. Just take the vector that connects from point A to point B, and multiply it by scalars from 0 to 1, and interpret the result as a displacement from point A. The set of all such displacements would generate the points you are talking about. It sounds like you are really asking "can the universe be embedded in a 4D spatial vector space if it is a 3 sphere at any given age", and I don't see why not, though it's not terribly clear what those points would mean because they would not be in our universe.