Hello Ralph,
Regrettably, this functionality is not available at the moment. The reason is that CMS.File is handled via GetFile.aspx.cs handler but attachments are not therefore it's not possible to track them.
On the other hand, if you want functionality like this available in the feature version of Kentico, you can suggest it and also other users will be able to vote for it (more users = higher priority), on the special page: Kentico UserVoice
Best regards, Martin