Password only alphanumeric no special character -MVC C#

Password matching expression. Password must be at least 4 characters, no more than 8 characters, and must include at least one upper case letter, one lower case letter, and one numeric digit.

Expression: ^(?=.*\d)(?=.*[a-z])(?=.*[A-Z]).{4,8}$

public class LoginViewModel

{

[Required(ErrorMessage="Required")]      

[Display(Name = "User name")]

public string UserName { get; set; }

[Required(ErrorMessage = "Required")]

[DataType(DataType.Password)]

[RegularExpression("^(?=.*\\d)(?=.*[a-z])(?=.*[A-Z]).{8,10}$", ErrorMessage = "Password Alphanumeric Only. Minimum length 8")]

[Display(Name = "Password")]

public string Password { get; set; }

}