Phpnuke news module modification

We need to modify our current php nuke based website in detail, the news module need to be modified. It needs to have a selectbox/checkbox while writing news in the admin back end if that particular news item is for everybody or just subscribers on the website. When choosing "just for subscribers" the read more of that article needs to be blocked from "normal" registered users and shown only to our subscribers. If left unchecked the article should be viable to everyone. This needs to affect only "read more" section of the article while the summary on the front page needs to viable by everyone.