The machinery for a moderated newsgroup works by the news server you post an article to having a list of moderator email addresses for moderated groups. Instead of posting your article the server emails it to the moderator. The mod will then either just discard it, or else post it to their own news server with an Approved header to say it's moderated (and these days some crypto signing stuff). Then the post gets propagated as usual.
The "approve/deny/edit" stuff is handled by moderation software, which in principle can do anything you like.
The "approve/deny/edit" stuff is handled by moderation software, which in principle can do anything you like.