Using what expression I can get ModelMetadata info for a single item from a collection?

Question

I have an application that is written using C# on the top of Asp.Net MVC 5.

I have the following model

public class SomeViewModel
{
    public IList<CheckBoxListItem> Days { get; set; }
    ......
}


public class CheckBoxListItem
{
   public bool Checked { get; set; }
   public string Value { get; set; }
   public string Text { get; set; }
} 

I want to be able to get the ModelMetadata for a single day aka CheckBoxListItem in the Days collection.

I tried the following to get the first day in the day's collection

// Attempt to get the ModelMetadata for the first item in the Days collection
ModelMetadata.FromStringExpression("Days[0]", html.ViewData); 

// Attempt to get the ModelMetadata  for the Checked property in the first item
ModelMetadata.FromStringExpression("Days[0].Checked", html.ViewData); 

But the above does not return the ModelMetadata.

The following code returns the whole collection as expected.

ModelMetadata.FromStringExpression("Days", html.ViewData); 

What is the correct expression to use to get the ModelMetadata for a single item in a collection?