Display sum of Handoff Date and Duration in custom report

On a project, we will have tasks that are sent to our Web Team to post online. Even if the project is behind, they still honor the same SLAs that are defined in our project templates. We are currently changing the Due On date to adjust for this but if the project is in an At Risk or In Trouble condition, that will be changed to On Target.

We do not use any custom forms at the task level so we would likely run into issues with calculated fields from a task custom form not being added. We have tried using the Project Completion date but we do not update the percent of the task so that date adds the duration to today's date.

So I was trying to figure out if there is a way to create a custom field on a report that will add the number of days in the Duration to the Handoff Date so we can see the date the Web Team should complete the task. Has anyone created a custom field similar to this? Or have any thoughts on how we can address this need?