Is there a way to add columns to the Row Total Formula in Zoho Books/Invoice?

Is there a way to add columns to the Row Total Formula in Zoho Books/Invoice?

By The Grace of G-D.

Hi,
How are you?

As you might know, in Zoho CRM, A user can edit the Formula of the Row Total so one can add a field to the Subform and add it to the calculation so it will affect the final price.

Can you do such a thing in Zoho Books?
Surely you can add fields to the table (by adding them in the Items module and choosing to show them in transactions).
but the amount in these custom fields is not calculated in the totals.

So, is it possible or not?