[Closed] wiring Z_scale with expression

Hi, I was trying to wire a box1 height changing the position of box2 (I have an expression controller that performs how and when the height value has to change)
It works fine, but I have many problems, due to my maxscript low knowledge, when I want to add other objects influencing the same parameter (box3, box4,…)
I tried to animate Z_scale instead of the heigh param (I intend to put a list controller with many Z_scale and to drive each controller with a different box), but wiring doesn’t work anymore (maybe the expression result isn’t the correct format). I tryied to find that in google, but I can’t achieve it or find a good example, what I made wrong?
many thanks
greetings