I am trying to populate an OutlineView with the contents of a XML file.

I'd like to create and manage the values inside a NSIndexPath while cocoa parses the document.
NSIndexPath has methods to add and remove indexes, but I need to increment/decrement the values in each index:

[0, 0]  

[0, 1]  

[0, 2]  

and so on...

how can I do that?