Urgent:Convert C++ Function Pointer to VB.Net

[setheo]

To all gurus,

I am currently converting some of C++ codes to VB.net

The C++ Codes is as follows :

================= C++ CODE ==================
typedef struct _tagBBCameraParameter
{
unsigned int preview_width;
unsigned int preview_height;
unsigned int preview_x;
unsigned int preview_y;
unsigned int preview_format;
unsigned int preview_zoom;

const TCHAR* capture_file_name;

unsigned int contrast;
unsigned int saturation;
unsigned int brightness;

} BBCameraParameter;

typedef LPVOID HBBCAMERA;

BBAPI DWORD WINAPI BBCameraPreviewStart(HBBCAMERA, BBCameraParameter*);
BBAPI DWORD WINAPI BBCameraPreviewStop(HBBCAMERA);

================= END C++ CODE ==================

I managed to convert most of the codes to VB.Net but when I try to fun BBCameraPreviewStart function, it gives error.

'=================Partial VB.Net Code


Public Shared Function BBCameraPreviewStart(ByVal HBBCamera As IntPtr, ByRef BBParam1 As BBCameraParameter) As Integer
End Function

Public Shared Function BBCameraPreviewStop(ByVal HBBCamera As IntPtr) As Integer
End Function

'=========== END OF PARTIAL VB.NET CODES

This is how i pass the parameters;

Dim BBParam as BBCameraParameter '// already declared but not shown here
Dim HBBCamera as IntPtr '//Handle

'I have no problems getting handle but once i set the parameters for BBParam and pass as follows, i get error (not much help from the message).

BBCameraPreviewStart(HBBCAMERA, BBParam)

How do I call function BBCameraPreviewStart correctly? Did i do it correctly?

Please advices.
Thanks