Thank you, Shiela and Clarisa! This answers my question.

Hi Angelica, appreciate your response. Please refer screenshots below. Set Field Value

Hi Alex, appreciate your response. The issue was resolved through scripting. Unfortunately, the NVL function didn't work. Thank you!

Hi Jack, I worked on similar use case - I created non-stored custom field, set up a workflow to display calculation ({custbody6}- {custbodymac1_}) and it did work! However, the formula isn't working when a Case When condition to convert negative (-) to zero (0) was added.

Hi Joahnna, Thank you for the response. Wells Fargo provided a file specification, so I was wondering if a custom payment file template is an option?