Sharing a structure between processes with memory mapped files

Hi:
Sorry if thisis th wrong group, but I hope somebody can help:
I am currently working on a project within wich I need to shae a structure
between processes.
The structure is defined in a namespace as follows:
struct SATreeviewInfo {

IAccessible* TreeviewAccessible;

VARIANT VarObject;

VARIANT VarObjectState;

HWND TreeviewWindow;

TV_ITEM CurrentItem;

LPWSTR Text[1024];

};

Late in the namespace declaration I define a variable of this type:

extern SATreeviewInfo TreeviewInfo;

In the main code module after creatin the memory mapped file and
initializing this to th size of the structure, the following code maps the
structure in to the process:

TreeviewInfo =(SATreeviewInfo)MapViewOfFile(HTreeviewMSAAMapFile, NULL, 0,
0, 0);

The error I obtain when compiling is:

1>c:\work\serotek\libserotek\treeview.cpp(26) : error C2440: 'type cast' :
cannot convert from 'LPVOID' to 'Treeview::SATreeviewInfo'

1> No constructor could take the source type, or constructor overload
resolution was ambiguous

As far as I know I'm not using a class. Can somebody point me to the
probjel? What is the fix. if it maters is visual studio 2005.

Sean.