I have searched all over and can't seem to find an answer for this. For each row, I am attempting to sum the values of the next x rows (3 in the example below) for each item.
Example: Item 1, row count for aggregation = 3, next 3 rows countain 10 in each row which equals a sum of 30. It only sums for the item that corresponds to the row that the sum calculation is on (similar to a group by).
The example below is far simpler than my real data which contains different values for sales for each row.
I am assuming that this would be an iterating do until loop of some sort but I can't seem to think of a strategy. Thanks for all of your insight!