Following up my discussion about list group by value :
I am now looking to write theses values into a shared parameter.
The problem is :
I have a list of 5 values
I have 31 rooms.
My first list (corner up right) is :
the number of an apartment (a shared parameter)
the total surface of all the rooms given this common number of the apartement.
The second list (corner down right) is :
the number of an appartement (same shared parameter)
the surface of the room
the Id (guess I’ll have to sort it by to write the right value ?)
the shared parameter (total surface of the appartement)
Now, i’m trying to do :
if any room in the project has the same value of List 1  “Apartement number” then you write the value  (previously calculated value) into the  (List 2)
I’m doing a == with cross product to get this true/false checking…Am i getting somewhere with this ? But i don’t know how to sort after that…
I checked that discussion but it’s for one value > one calculated value…
I must say i’m kinda lost here…