When we finally started to use iteration plan, we have accumulated hundreds of unplanned work iteams. And I tried add some of them to the new iteration plan following the method from the Jazz documentaion:
To add work items to a plan:
1.Select an entry in the Work Items view and drag it to the Planned Items page. Drag it to a user or category to assign it. Drag it to a work item to make it a child of the work item.
2. Modify an existing work item so that its category and planned iteration match the criteria for the iteration plan.
3.Create a new work item. Right-click a group folder or a work item and click Add Work Item and select a work item type.

But 1 seems to work only for those already in the Planed Items panel; For the unplanned ones, they are not selectable or dragable in the Work item view;

As for 2, I can locate/modify an item's category, but can't locate its planned iteration, the closest one is its Team Area filed which show the development line; how do I modify their planned iteration property to make them show up in the new iteration plan?

3 works fine but won't help the existing unplanned ones.

So how do I add the existing unplanned work items to a new iteration plan?