I am understanding that you want to add the row item to the collection?
I’m assuming Company is an Array or List, which won’t work as Collections. And, arrays have a fixed length, but one method would be to recreate the array with the added item. (ie
(String.Join(",",Company)+","+FileString(0).ToString).Split(","c) … so it joins the array, concatenates the new item, then splits it back to an array)
However, I actually would recommend using a Collection. You can do this by using the Build Collection activity, and then when you want to add to it, use Add to Collection.
It would look like this:
Where you place the Company list into the Collection property of the Build Collection activity, then use a Collection variable type in the Result property. Lastly, just place the row item into the Item property of the Add to Collection, and adjust the Type property accordingly.
EDIT: place the Add to Collection inside the Loop, while the Build happens at the beginning.