Lynn,

I would suggest that my story - "Thanksgiving in Smallville" would be an example of a guest star and not an original character.

Here's the set-up:

Kam-El and Ultra Woman 2 are assisting Superman and Ultra Woman with an earthquake clean up. Superman and Kam-El rescue two women from a collapsed roof.

The two women turned out to be Teri Hatcher and her daughter Emerson. Hardly original characters, but guest stars in this story.

Herb replied, “My boy, I never say … impossible.” "Lois and Clarks"

My stories can be found here

kj