I have a web form with a programmatically generated DataGrid.  The DataGrid
columns are defined at run-time based on a SQL query.  A class is derived
from ITemplate to handle a fixed set of column types.  Here is a code
fragment:

namespace ApplianceBook
{
   public enum DisplayType
   {
       Fraction = 1,
       Percentage = 2,
       Integer = 3,
       Decimal = 4,
       String = 5
   }

   public class CTemplateColumn : ITemplate
   {
       private ListItemType columnListItemType;
       private string columnName;
       private int columnWidth;
       private DisplayType columnDisplayType;

       public CTemplateColumn(string ColumnName, int ColumnWidth,
ListItemType ColumnListItemType, DisplayType ColumnDisplayType)
       {
           columnName = ColumnName;
           columnWidth = ColumnWidth;
           columnListItemType = ColumnListItemType;
           columnDisplayType = ColumnDisplayType;
       }

       public void InstantiateIn(Control container)
       {
           switch (columnDisplayType)
           {
               case DisplayType.Fraction:
                   Label labelFraction = new Label();
                   labelFraction.ID = columnName;
                   labelFraction.Width = columnWidth;
                   if ((columnListItemType != ListItemType.Header) &&
(columnListItemType != ListItemType.Footer))
                   {
                       labelFraction.DataBinding += new
EventHandler(this.OnDataBindingFraction);
                   }
                   container.Controls.Add(labelFraction);
                   break;

               case DisplayType.Percentage:
                   Label labelPercentage = new Label();
                   labelPercentage.ID = columnName;
                   labelPercentage.Width = columnWidth;
                   if ((columnListItemType != ListItemType.Header) &&
(columnListItemType != ListItemType.Footer))
                   {
                       labelPercentage.DataBinding += new
EventHandler(this.OnDataBindingPercentage);
                   }
                   container.Controls.Add(labelPercentage);
                   break;

Everything works as expected and I am able to modify the actual text in each
cell based on its ColumnDisplayType.  However, I also want to be able to
format individual DataGrid cells based on ColumnDisplayType.  For example, a
cell with a ColumnDisplayType with percentage data should have its cell
background color set to red if the data value is greater than 50%.  Here is
my event handler for the Percentage column type:

public void OnDataBindingPercentage(object sender, EventArgs e)
{
   GridViewRow container;
   if (sender.GetType().ToString() == "System.Web.UI.WebControls.Label")
   {
       Label label = (Label)sender;
       container = (GridViewRow)label.NamingContainer;
       // Format data to display as a percentage value.
       label.Text = String.Format("{0:0%}",
((DataRowView)container.DataItem)[columnName]);
   }
}

In the above code I am able to access the data stored in the cell via
((DataRowView)container.DataItem)[columnName] but I can't find a way to
access the cell object containing the data so that I can apply cell-level
formatting.  The container object doesn't seem to support accessing a
particular cell in the row using the the columnName as an index.

I want to be able to do something like the following (fictitious) code:

if (((DataRowView)container.DataItem)[columnName] > .5)
{
   ((DataRowView)container.DataItem).Row.Cells[columnName].BackgroundColor
= Red;
}

Unfortunately, DataRowView.Row does not have a Cells property.

How do you access the DataGrid cell associated with the current databinding
event?  Any instructions or sample code for doing so would be a big help.  
Thanks.