We want to create a Reader Bar (means of highlighting the active row,
column, or both) using conditional formatting. However, we do not
immediately find a worksheet information function that will identify the
address of the active cell. Obviously, this information is essential to
triggering the conditional format. Does anyone know of a worksheet function
that will identify the active cell?

Now to add a twist. If the current selection is not a single cell (but a
row, column, or range), we do not want to trigger the reader bar highlight.
In other words, we only want to trigger the conditional format if a single
cell is selected.