Excel 2007 and 2010 narrow down filtering

Setting the grid.FilterDropDownAuto and grid.FilterDropDownCheck to true works brilliantly for emulating the narrow down filtering functions in Excel 2007 and 2010.  Thanks very much for continually improving these properties.  I have two questions:

1. Is it possible to progarmmatically (or otherwise) add a "Select All" checkbox at the top (as in Excel 2007+) that allows the user to select and deselect "all" of the column filter dropdown checkboxes?

2. How do I access just the filtered, displayed data for a specific column?  For example, I would like to load the filtered data only into an array for other data manipulations, such as for statistical analysis or for display in a chart.


I just upgraded AdvStringGrid from version to and I am still having problems using the auto filter drop down.  For example, open AdvStringGrid example 56 and make the following changes:
   FilterDropDownAuto = true
   FilterDropDownCheck = true
   FilterDropDownCheckUnCheckAll = '(Select All)'
Complile and open an Excel worksheet containing a dataset.  I uploaded an example dataset that can be downloaded using the following link: https://app.box.com/s/agtr8rz08ovu7hiklqze

The auto filter behaves erratically.  For example, from column 2 pick "alkyl lead plant" and then from column 4 pick "WorkerF", then "WorkerA".  Instead of adding WorkerA rows to the WorkerF rows, all rows disappear.  Picking other selections from columns 2 and 4 leads to other erratic behaviors.  Sometimes the "Select All" refuses to work.

Is there something that I should be doing programmatically to get the FilterDropDownAuto filters to work as they do in Excel 2010?