Do you mean anchored, as in an object that is locked into a certain postion and moves with the text when editing, or do you mean threaded, which is the term for connecting a series of text frames together to to have text flow in a continuous stream running through them?
In the case of an anchored object, the object should be coming along when you copy the frame that contains the anchor. In the case of a threaded story, if you want the entire story you must select the text, not the frame, and copy that.
I mean a threaded story. Our xml-export solution is copying text-boxes, and when we have stories over 3 or 4 pages, all the text after page 2 is deleted (One spread can be grouped, but 2 spreads can not..) Very frustrating. So I hoped Indesign had an "hidden" option-box where I cold choose to keep all the text when copying a text-box...
More detail please. Your XML solution is a plugin? Or a script?
It seems strange that it would be worrying about boxes. It should be dealing with Stories, not with TextFrames.
But it sounds like it has an interactive element? [??]