how can i read the header text from a datagrid when autogeneratedcolumns="true"

Question

I have chosen to use a datagrid with the autogeneratecolumns="true" because I do not know in advance how many columns will be loaded. I've also included an item template to allow selection of a row for editing. When the edit item command fires, the datagrid is hidden and a new panel made visible where dropdownlist controls are genearted based on the number of columns.

I need to inspect the selected column's header text. How can I extract the selected column's header value when autogenerate is true?

Thanks in advance