Left hand side assignment in C# error
===

I am converting some VB code into C#.
In VB the code looks like the following:

        
    oTP.CreateObject("SomeInterop")    
    oTP.Session("SomeKey") = 5

In C#, if I do:

    oTP.Session("SomeKey") = 5;

I get a compilation error, "The left-hand side of an assignment must be a variable, property or indexer".
In VB, oTP is declared as an object and in C#, i declared it as dynamic.
In the oTP code, Session looks like this:

    Public Property Session(ByVal VariableName As String) As Object
    Get
    ....
    End Get
    Set(ByVal Value As Object)
    .....
    End Set

