using System;

using System.Collections.Generic;

using System.Linq;

using System.Linq.Dynamic;

​

public class Program

{

    public static void Main()

    {

        var lstContacts = new List<Contact>{

            new Contact{Id = 1, Active = true, Name = "Chris"}, 

            new Contact{Id = 2, Active = true, Name = "Scott"}, 

            new Contact{Id = 3, Active = true, Name = "Mark"}, 

            new Contact{Id = 4, Active = false, Name = "Alan"}};

        string columnName = "Active";

        List<Contact> results = lstContacts.Where(String.Format("{0} == true", columnName)).ToList();

        foreach (var item in results)

        {

            Console.WriteLine(item.Id.ToString() + " - " + item.Name.ToString());

        }

    }

}

​

public class Contact

{

    public int Id

    {

        get;

        set;

    }

​

    public bool Active

    {

        get;

        set;

    }

​

    public string Name

    {

        get;

        set;

    }

}