gistfile1.cs

using (var mongo = Mongo.Create("mongodb://user:password@localhost/Test"))
{
    // Some strongly typed filter, I want a document with a number of 2
    Expression<Func<User, bool>> filterExpression = u => u.Number == 2;
                
    // A NoRM specific object, not important
    var filter = new Expando();

    // I need to pull the name "Number" and the value 2
    // and programatically pass it to the NoRM expando object.
    // IE: filter.Set("Number", 2);
    // This is psuedocode here of course:
    foreach (var filter in filterExpression.Body)
        filter.Set(filter.Name, filter.Value);

    // NoRM specific, not important
    var user = mongo.GetCollection<User>().FindOne(filter);
    Console.WriteLine(user != null ? user.Name : "Nothing found");
}