How to extend iWork's Number'09 formulas?

I have specific formulas that I'd like to write (in Objective-C perhaps) and integrate with Numbers'09 of Apple's iWork sui开发者_开发问答te in iPad and wonder if there is such a way to do so?

For Numbers on Mac OS X:

I don't think there's a supported way to do so. All functions in Numbers are hard-coded in /Library/Application Support/iWork '09/Frameworks/SFTabular.framework/Versions/A/SFTabular. You need to use tools like SIMBL to modify the classes in it at runtime.

For Numbers on iPad:

Even worse than the Mac version. There's no way to have an interpreted language in AppStore, not to mention an official way to support third-party plug-ins!

The first thing to do is to jailbreak your iPad, which allows custom code to be run. Then you need to wait for saurik and iPhone dev team to patch the kernel and release MobileSubstrate for iPad. When these prerequisites are satisfied, you need to analyze how Numbers.app create those functions (that means someone needs to crack it first) (I believe it's similar to SFTabular), and write a patch as a MobileSubstrate dylib.

There is not any approved way to do this, so specifically considering the iPad, even if you manage to hack it up and get it to work, your hack would not be welcome in the App Store.