MySQL EXDI: Where does AdHoc SQL get field values

I've got the beginning of a MySQL EXDI interface working but can't
figure out where AdHoc SQL and sessions discover column values.

#nextRowExternal is returning rows, the column headers are correct, and
the table properly knows the number of rows to display, and their widths
seem reasonable, but the cells are empty.

Where does it get the data?

--
Visit <http://tggagne.blogspot.com/>,<http://gagne.homedns.org/> or
      <http://gagne.homedns.org/~tgagne/> for more great reading.