ASP.NET GridView second header row to span main header row

I took the accepted answer approach, but added the header to the existing GridView instead of a custom inherited GridView.

After I bind my GridView, I do the following:

/*Create header row above generated header row*/

//create row    
GridViewRow row = new GridViewRow(0, -1, DataControlRowType.Header, DataControlRowState.Normal);

//spanned cell that will span the columns I don't want to give the additional header 
TableCell left = new TableHeaderCell();
left.ColumnSpan = 6;
row.Cells.Add(left);

//spanned cell that will span the columns i want to give the additional header
TableCell totals = new TableHeaderCell();
totals.ColumnSpan = myGridView.Columns.Count - 3;
totals.Text = "Additional Header";
row.Cells.Add(totals);

//Add the new row to the gridview as the master header row
//A table is the only Control (index[0]) in a GridView
((Table)myGridView.Controls[0]).Rows.AddAt(0, row);

/*fin*/

Note for those who choose to use RowDataBound Method in VB.NET

If you end up with too many extra header rows popping up, add an If Statement that only proceeds if the gridview's header row is nothing (meaning it is the one currently being bound)

 If grid.HeaderRow Is Nothing Then

This article should point you in the right direction. You can programmatically create the row and add it to the collection at position 0.