You don't want to use SelectByID2 for this.
You should loop through all the faces in all of the bodies in the model.
For each face, if it has the desired appearance, convert it to an IEntity object and use IEntity.Select4
For the last bit:
Dim swEntity as Entity
Set swEntity = swFace
swEntity.Select4 True, Nothing
Thanks a lot. That was exactly the thing I was aiming for!