Returns the path to the private Mapi32.dll.
[in] The MSIComponentID reg key described in Mapi32.dll Stub Registry Settings.
[in] The MSIApplicationLCID or MSIOfficeLCID subkey described in Setting Up the MSI Keys for Your MAPI DLL. Callers can pass NULL if there is no qualifier.
[in] The path to the private Mapi32.dll, which has full MAPI functionality (the same exports as the Mapi32.dll).
[in, out] The size of szDllPath, in characters.
[in] Tells MAPI to install the private Mapi32.dll component if it is absent.