Troubles with API call

I just try to make a DllImport with the following api (in oleacc.dll) and I have troubles with the IAccessible** parameter

STDAPI AccessibleObjectFromPoint(
POINT ptScreen,
IAccessible** ppacc,
VARIANT* pvarChild
);

Anyone has an idea ?
Thx

I think you have to make IAccessible a delegate.

using the object type I get some values but less than my ocx done in c++