How to Interop 2D char in c#

[C# Programming]

I have written a COM DLL which gives the
out parameter as BSTR**(Typically 2D Char Array).

This COM function will fill the values of BSTR** variable.

I am able to use this function sucessfully in MFC Application.
But I face problem in using it in C#.

The Sample code is as follows:

///////////COM Function////////////////////////////////////////
STDMETHODIMP CSampleTest::GetAllDeviceList2(BSTR** szMaclist)
{
AFX_MANAGE_STATE(AfxGetStaticModuleState());

for(int i=0;iGetAllDeviceList2(szMaclist);
pText->Release();
}
and i am sucessful in acessing this function in MFC Application.

Can anyone tell me how to acess GetAllDeviceList2() function in c#.