public class Column<T>

{

     public string Name { set; get; }

     public T Data { set; get; }

}

IList<Column<T>> myList = new List<Column<T>>();

using System.Collections;



namespace Tests

{

    public interface IColumn

    {

        string Name { set; get; }

        object Data { set; get; }

    }



    public class Column<T> : IColumn

    {

        public string Name { set; get; }



        public T Data { set; get; }



        object IColumn.Data

        {

            get { return this.Data; }

            set {  this.Data = (T)value; }

        }

    }

}

var myList = new List<IColumn>();

var myList = new List<IColumn>

{

    new Column<int> { Data = 1, Name = "Col1"},

    new Column<double> { Data = 1.2, Name = "Col2"}

};

static T GetColumnData<T>(IList<IColumn> list, string name)

{

    var column = (Column<T>)Convert.ChangeType(list.Single(s => s.Name.Equals(name)), typeof(Column<T>), null);

    return column.Data;

}

int data = GetColumnData<int>(myList, "Col1");