Editable Pivot table values

Hi,

I have a dataset of thousands of articles which i have put in a pivot table (see attached example for one article).
It shows me forecast quantity, sales order quantity, forecast proposition and sales order qty from last year.

Now I would like to create a new forecast inside the pivot table, so i need to have that line to be editable.
I heard about inserting "calculated item", and I tried some things, but I cant get it to work.

Hi Gaellus:
Stolen from another forum:
"No, you can't add a column to the middle of a pivot table.

As a sort of workaround, if your pivot table is in columns A:C, you could, however, set E1=A1 copied down, F1=B1 copied down, leave column G blank, and set H1=C1 copied down

Then, E:H would show the data from the pivot table and give you the flexibility to add comments to column G."

https://www.mrexcel.com/board/thread...-table.384837/