To make this reusable across your workbook, you can name the function by going to the Formulas tab > Name Manager > New, and then assign a name to the LAMBDA function (e.g., AreaOfRectangle).

Formulas are powerful tools for performing calculations and analyzing data in Excel. In this beginner’s guide, you’ll learn how to use formulas and explore some popular built-in functions.

How to Enter, Edit, or Delete Formulas in Excel ...

Writing Excel formulas isn't easy if you don't speak the language. Fortunately, at least two sites will translate your request, in English, into Excel code.