Hooking File Calls

I need to be able to intercept any applications such as MS Word's call to Open or Save a file, and replace it with my own routine. Is this possible with VB and the API ?, anyone have any pointers ?

You would need to subclass their WM_COMMAND message. In order to subclass other windows you would need to put the WindowProc in A DLL file because processes can't access other processes memory area. A dll can be accesed by any process. The dll can't be made in VB. It can be made in c++.

Are you saying that if the application uses a standard windows file dialogue I can trap it by subclassing the WM_COMMAND, but if not I would have to use c++. I am interested in what the limitation would be, as I am not a C++ programmer,

Thanks for your reply