Reply to Loading Samples in S4

I just got the s4 and i'm loving it. only thing i'm curious about is how to load samples that you've previously made. What i mean by that is, when you load in a song and make a sample for it, then go back another day load in the same song, how do i get those old samples back in? i know that all samples i make are saved as wav. files but i was hoping there would be a way to assign them to the track they came from so whenever i bring up that track the samples are loaded in as well. is this possible?