is there any alternative for Any keywork in .net

Question

Hi,
I have migrated ActiveX (VB6) project in .net (.exe type project)    Is it right ?
after migration I am getting some errors

1- For VarPtr (vb6 function) any alternate function in .net

2- In my application used  CopyMemory Lib "kernel32" with paratmeter any.
   I tried by replacign any with object not working.

3- One structure is there and passing object of structure to CopyMemory function
    
    Public Structure udtGUID
        Dim Data1 As Integer
        Dim Data2 As Short
        Dim Data3 As Short
        <VBFixedArray(7)> Dim Data4() As Byte       
        Public Sub Initialize()
            ReDim Data4(7)
        End Sub
    End Structure

   
 Dim rClsId As udtGUID
 CopyMemory(rClsId, riid, Len(rClsId))

Is there any alternative for CopyMemory in .net

Thanks