Get API_ObjectType parent/owner

[ReignBough]

I am trying to get the parent/owner wall of the object I created using Design > Design Extras > Accessories > Wall Accessories.

When checking the objects structure, these values are zeroes:

typedef struct {
    // ...
    API_ElemType            ownerType;
    API_Guid                owner;
    // ...
} API_ObjectType, API_LampType;

Is there any other function that I don't know of that can do the trick?