using (PrincipalContext PC = new PrincipalContext(ContextType.Domain, "165.1.5.25",
"OU=Test,OU=Users,OU=Domain,dc=test,dc=dom", Environment.UserName, "admintest"))
        {
            using (UserPrincipal UsrP = new UserPrincipal(PC))
                try
                {
                    UsrP.Name = "testuser";
                    UsrP.SamAccountName = "testuser";
                    UsrP.GivenName = "Test";
                    UsrP.UserCannotChangePassword = false;
                    UsrP.PasswordNeverExpires = true;
                    UsrP.SetPassword("Qwerty123");
                    UsrP.Enabled = true;
                    UsrP.Description = "000";
                    UsrP.EmailAddress = "testuser@test.ru";
                    UsrP.VoiceTelephoneNumber = "2222";
                    UsrP.Surname = "User";
                    UsrP.DisplayName = "Test User";
                    UsrP.UserPrincipalName = "testuser@gfx.dom";
                    UsrP.Save();

                    UserPrincipal user = UserPrincipal.FindByIdentity(PC, "testuser");
                    GroupPrincipal group = GroupPrincipal.FindByIdentity(ctx, "TEST_GROUP");
                    group.Members.Add(user);
                    group.Save();
                }
                catch (Exception ex)
                {
                    _Log(ex.Message);
                }

        }

[DirectoryRdnPrefix("CN")]
    [DirectoryObjectClass("Person")]
    public class UserPrincipalEx : UserPrincipal
    {
        public UserPrincipalEx(PrincipalContext context) : base(context)
        { }

        public UserPrincipalEx(PrincipalContext context,
                             string samAccountName,
                             string password,
                             bool enabled) : base(context, samAccountName, password, enabled)
        { }

        [DirectoryProperty("physicalDeliveryOfficeName")]
        public string Office
        {
            get
            {
                if (ExtensionGet("physicalDeliveryOfficeName").Length != 1)
                    return string.Empty;

                return (string)ExtensionGet("physicalDeliveryOfficeName")[0];
            }
            set { ExtensionSet("physicalDeliveryOfficeName", value); }
        }
    }