How do I marshal a C# string array to a VB6 array?

I have a VB6 app that uses a C# COM DLL. In managed C++ I can write a function as follows:

array<String^>^ GetAManagedArray()
{
    //Do stuff and return a managed array
}

I can then assign the returned managed array to an array in VB6:

Sub MySub()
    Dim strArray() As String
    strArray = myComObject.GetAManagedArray
End Sub

This works fine in C++, but in C# the System.Array object is abstract and I can't seem to find the managed equivalent to the C++ array<>^. Also, in C# just returning string[] does not work.

What is the managed array equivalent in C#?

EDIT: Here is the exact code I have for the fucntions
The C# COM function:

public string[] OneTwoThree()
{
    return new string[] { "1", "2", "3" };
}

The VB6 function:

Private Sub Form_Load()
    Dim test As New ComObjectCSharp
    Dim strArr(), strTemp As String
    strArr = test.OneTwoThree
    strTemp = strArr(0) & " " & strArr(1) & " " & strArr(2)
    MsgBox strTemp
End Sub

The code fails on the fourth line of the VB6 code with the error "Compile error: Can't assign to array"