Posterize motion

Hallo all,

I am looking to simulate a radar display in after effects for a promo. The radar display has a plot (the location of the return), histories (last 3-5 locations of the plot) and a label. The position of the plot changes at every refresh which is about 5 seconds. I will do it at .3 seconds for effect.

Here's the problem. The plot and the label needs to "jump" every .3 seconds, not every frame. However I can't use posterize time because the label has additional animation (user interaction) that is in real time. I am looking for something like posterize motion.

I have tried creating a null and creating the motion in that, then create a subcomp with the tag (possition tied to the null) and using posterize motion into that but I still can't animate the tag meanwhile.

Any ideas?
--eric