Integrating Numbers (Excel style Addins) by using Applescript and Xcode or Python

Excel VBA allows me to create additional (adding) functions. I am hoping to do the same with Numbers. What is the best approach? I assume that Xcode will be an extremely efficient calculator. Any opinions: would Python be a better alternative (Binding arguments & Scripting) for the calculation routines. In all cases an additional open point would be how to manage passing arguments back & forth? Thx.

AppleScript gives you a way of getting data to and from Numbers documents. For manipulating that data, AppleScript’s mathematical tools are very basic. Xcode is a development environment, not a calculator.
Depending on what you’re doing, you might need to use a combination of tools.