I'm writing an ActiveX control. In one of the functions I'd like the user to be able to pass me a pointer to a buffer that they created which I can then fill with data and return a success/error code. What's the appropriate way to do this? I was thinking about just using an OLE_HANDLE type for the parameter and then casting that to pointer inside the OCX but I'm not sure if that's safe or the right way to do it. Any suggestions or advice?