Protected Friend Property Item ( _
    prop As ConfigurationProperty _
) As Object

Dim prop As ConfigurationProperty
Dim value As Object

value = Me.Item(prop)

Me.Item(prop) = value

protected internal Object this[
    ConfigurationProperty prop
] { get; set; }

protected public:
property Object^ Item[ConfigurationProperty^ prop] {
    Object^ get (ConfigurationProperty^ prop);
    void set (ConfigurationProperty^ prop, Object^ value);
}

JScript does not support indexed properties.