In help file said that: Methods listed inside description string must be in v-table order of the interface. how do you know this order? For example: i try to create IEnumUnknown interface http://msdn.microsoft.com/en-us/library/windows/desktop/ms683764(v=vs.85).aspx It has members: Clone, Next,Reset,Skip But as will be correct? $dTag_IEnumUnknown = _ "Clone hresult(ptr*);" & _ "Skip hresult(ulong);" & _ "Next hresult(ulong;ptr*;ulong*);" & _ "Reset hresult();" or $dTag_IEnumUn