Heiko, you would need to add additional tags for your additional data fields:
--copy the kt_document_template.htmpl file from
sdm-install\bopcfg\www\htmpl\default
to sdm-install\site\mods\www\htmpl\default and then modify this file in sdm-install\site\mods\www\htmpl\default to add additional tags for the data fields you would need to add to the knowledge template
--log into sdm web interface as administrator and then Administration->knowledge->documents->document templates
and right click on the template you would like to modify and choose edit and then add the tags you added to the kt_document_template.htmpl file
--run "pdm_webcache -H" on the sdm server and on browser side clear/delete the temp files
--test
Hope this helps. Thanks _Chi