How to trans parameter to PostThreadMessage in C#?

[cowboycool]

Someone had written a function such as
Void SendData(CWinTh read *p)
{
p->PostThreadMess age(WM_GetData, 0,0)
}
in a MFC DLL,Now I want to get the message from this DLL through a C# thread ,how can I trans the parameter *p to the DLL?