Proceedings are the papers themselves, or increasingly these days abstracts. Conference journal papers are usually a selection of papers, sometimes by track or that particularly focus on the conference theme published in the journal associated with the conference. Sometimes these are developed versions of the papers. In either case, you can count them as journal publications.
In a nutshell, Proceedings are just conference papers (published in a particular conference book/e-book). Nowadays most of the renown and prestigious conferences ask for few selected authors (from that particular conference) to submit the extended version (you need to add more research works than that of conference proceedings) of that proceedings to publish in a Journal for Special Issue (in few cases regular issue). Mostly this 'Conference Journal Publication' is a kind of new publication, and you can consider it as a journal publication as Dag Bennett mentioned.