I think you need to create an additional PDF file and then use the "AdditionalFilesPostPublishDelegate". From the documentation:
Once publishing is complete and a representation is stored, the AdditionalFilesPostPublishDelegate copies the content (additional files) of the representation to a WTDocument. This is done to give enterprise control and visibility of the published content separately from the CAD Document structure, while maintaining a record of the association through a PublishedContentLink. Also, the additional files may be deleted from the original representation using the delete-original <post-publish> parameter.