That's a really good question.
There's probably lots of ways to do it, but I played around and found 2 possibilities. You can download my capx here.
Press "space" to run a cycle. The orange blocks use the sine behavior, and the blue ones use bullet. Neither method gets you the exact position you want, especially if the framerate varies, so both sets of blocks set their positions explicitly when a cycle ends.
If I only had these 2 to choose between, I would probably go with sine. You might be able to play with the "period" settings and the duration of the timer to get motion closer to exactly what you want.
P.S. Google drive is a little weird for capx files. When the screen comes up, just click the download button at the top.