Moderation per user?

All though you can use the permission system to have 'Post Approval' for a specific user, in your case the simplest way to do this is to enable the 'Post Approval' for the starter group so that new members require their posts to be approved.

We currently use this method in these forums where the new members are placed in the newbie group and require their posts to be approved, till they reach 10 posts when they automatically move up to the next group where they no-longer need their posts approving.