Advanced Excel Formula Creation

I need a specialist who can build robust, reusable Excel 365 formulas for an existing workbook. The work centres on creating truly advanced logic rather than simple cell references. In practical terms, every formula you write must:

• include reliable error handling so any #N/A, #DIV/0! or similar issues are gracefully managed
• use nested functions where they provide the cleanest, fastest solution
• trigger conditional formatting rules that instantly flag results requiring attention

I will supply a sample file with annotated targets and a brief “business-rules” document describing what each output should show. Your job is to translate those rules into efficient formulas, test them in Excel 365, and return the updated file together with a short explanation sheet so I can maintain or extend the logic later.

The work is complete once all fields calculate correctly across a range of test cases and the conditional formats react as intended without slowing the workbook.