C# - Binding To A List <string> Using DataBinder.Eval?

I have the following object:

CrossTabDataObject
{
string RowName{get;set;};
int RowId{get;set;}
List<string> CellContents = new List <string>();
//Constructor..... etc.
}

I'm building a dynamic crosstab grid using GridView in asp.net 3.5

I wish to bind to CellContents[0] for dynamic column 1, CellContents[1] for dynamic column 2 (dynamic column 0 is the RowName field from the CrossTabDataObject) etc. I am using:

object boundValueObj = null;
Control ctrl = (Control)sender;
IDataItemContainer dataItemContainer = (IDataItemContainer)ctrl.NamingContainer;
boundValueObj = DataBinder.Eval(dataItemContainer.DataItem, strSelectedID);

This code is in the InstantiateIn function of the gridview as I'm creating drop down list templates in each cell of the crosstab.

I have code (not shown) that sets strSelectedID depending on the column being created.

When strSelectedID is equal to "RowName" for dynamic column [0] the DataBinder.Eval function works fine and sets boundValueObj as expected. The problem comes when strSelectedID is set to "CellContents[n]" where n is the Column Index.

DataBinder.Eval only works with properties and fields of objects. How do I get around this?