status = Entity->Select4 (Append, Data, &retval  ).

From the face i am using the query interface to get the entity.But it is returning NULL.the code is here

status=FaceObj->QueryInterface(__uuidof(IEntity), reinterpret_cast(&swThisEntityObj)).

i have also tried with another code.

status = FaceObj->QueryInterface(IID_IEntity,  (void**)&swThisEntityObj);

I am new to this.

if any body knows any other method please tell me.

in VB .they are just assigning the entity with the face and using the select4 method.

entity=face2

In the solidworks API  another method I saw

status = ModelDocExtension->SelectByID2 ( Name, Type,  X, Y, Z, Append, Mark, Callout, SelectOption, retval )

there it is written  in the remarks that

"If your application already has an object handle (for  example, Face2), use the appropriate Select method to select the item directly  using its handle."

can any body suggest  me what method i will use for the face  to select