This is a pretty old tool. I think you want FEBuilder instead:
There are a number of little tutorials about febuilder. I would recommend checking the event templates while using it if you are stuck with something.
The above thread includes lots of info too. For example, this linked guide adds reinforcements which is similar to what you’re trying to do:
https://dw.ngmansion.xyz/doku.php?id=en:guide:febuildergba:reinforcement_en