Got it.
opacityController = thisComp.layer("mover").transform.position[0];
range = 96;
min = (index-1)*range;
max = (index+1)*range;
if ((opacityController > min) && (opacityController < max)) 100 else 0;
Motion Designer / DJ / Father
http://www.lukaszpason.com
http://www.krop.com/lukasz