Adding Custom formula field to a project

I've submitted a request to Zoho on this, but am wondering if anyone has a solution that is already workable.

I want to be able to add custom formulas to a Project. I know I currently can add a formula field to a Task layout, but I don't currently have that option for the Project level layout.

Here's a sample use case: We will track the estimated revenue (currency field) from a given project. We also track a "Project Probability" for that same project. From there, I would like to be able to multiply those two fields together and show the result on the project itself.

I know I can do such a thing in Analytics, but it would be VERY handy to be able to show this on the project itself.

I looked briefly at the idea of a workflow to do this, but it doesn't appear to be able to handle math, only hard coded values, when updating a field.

I'll admit that I'm new to Zoho administration, so any (gentle) guidance you can provide would be appreciated.

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