how to put DisplayName on ErrorMessage format

I have something like this:

    [DisplayName("First Name")]
    [Required(ErrorMessage="{0} is required.")]
    [StringLength(50, MinimumLength = 10, ErrorMessage="{0}'s length should be between {2} and {1}.")]
    public string Name { get; set; }

I want to have the following output:

• First Name is required.
• First Name's length should be between 10 and 50.

It is working when using ASP.NET MVC2 Error Summary, but when I try to validate it manually, like this:

        ValidationContext context = new ValidationContext(myModel, null, null);
        List<ValidationResult> results = new List<ValidationResult>();
        bool valid = Validator.TryValidateObject(myModel, context, results, true);

The results are:

• Name is required.
• Name's length should be between 10 and 50.

What's wrong? Thanks.