How to create a new field using IterationPath as data source

Question

We want to extend the bug work item template with a new field called Found In Iteration. This field, what a surprise, should contains the iteration the bug was found in. But when I created the new field of type TreePath, I got an error when importing the process template into the Team Project Collection (TPC) stating that TreePath is only a valid field type for IterationPath and AreaPath fields.

Looking at that I'm wondering if there is at least any way to add a field to a work item template that uses the iteration path as data source and stores the selected value in another field (e.g. FoundInIteration).

Answer 1

This is not possible. There can neither be custom fields of type TreePath nor fields refering to System.IterationPath.