Use array of interface that return from a COM object

Question

I have a COM dll (native) that I want to use it in my c# project, this dll has a function that get one IntPtr parameter like this :

int GetParameter(out paramCount,IntPtr paramInterfaceArray)

when I pass a IntPtr variable to the function runs without any error, BUT after call function when I want to use paramInterfaceArray to read array of param Interface I got error Access violation executing location . I tried many ways for solve problem but any one works. can anybody help me?