How to zero out subsequent cells in a field so data is not duplicated

[MrJWoo]

I am merging data from my invoice register that is at a sales order level with data from a costing module that can have multiple rows of data (sales order followed by 4 digit job suffix). The problem I am having is that while I do want multiple rows of data, I do not want the field Invoice Amount to be populated on every row. The invoice amount should only show up once for a sales order, and all subsequent rows until the next sales order for the invoice amount should be zero. Below is an example of the data I currently have, and then what I would like it to look like afterwards. 

Before

After

[ShankerV · Accepted solution]

Hi @MrJWoo 

One way of doing this.

IF [Order Number]=[Row-1:Order Number]
THEN 0
ELSE [Invoice amount]
ENDIF

Input was:

Note: Cant duplicate the entire dataset as it was pasted as screenshot, but the same replica will work in your huge dataset too.

Many thanks

Shanker V

[MrJWoo]

Thank you ShankerV, that did the trick! I was thinking of a similar way to do it in Excel but wasn't sure how to translate that into the IF statement in the formula tool. Appreciate the help!