get access to a list change information and store changes

heya.

i try to change the (x-,y-,z-)coordinates of points within a point grid and store the single changes within the list.

i've got no idea howto do the "store if change" thing - i've played around with some bake commands and rebring the data to gh - not very successfull at all.

the image below shows the problem simplified to a list of 10 points (without the store/buffer/cache option)

i hopefully made it to describe my problem simple and comprehensible;

thx for every hint.