Yeah - I saw that post.  It didn't really help me.  I found a different solution.  I am not sure this is the best/cleanest solution, but this seems to be working for me:

1.  on the "sorting" event, set a converter for the field to return the data value from the second column name

2,  on the "sorted" event, reset the converter to null

Here is the code:

private void dgData_Sorting(object sender, Infragistics.Windows.DataPresenter.Events.SortingEventArgs e)
{
   if (e.Field.Name == "Column1")
   {
      e.Field.Converter = new PriorityConverter();
   }
}

private void dgData_Sorted(object sender, Infragistics.Windows.DataPresenter.Events.SortedEventArgs e)
{
   if (e.Field.Name == "Column1")
   {
      e.Field.Converter = null;
   }
}

...
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
   DataRecord dr = (DataRecord)parameter;
   return dr.Cells["Column2"].Value;
}

Hello Ron,

Thank you for your feedback. I am glad that you resolved your issue and I believe that other community members may benefit from this as well.

Thanks again.