Preview on Access Restricted Content

I’m wondering.

I’m retrying UM, on a very large news site.

I want to make access restrictions on a lot of the content, and can not find any help/features like that anywhere. But I want to let non-members only read a short part of the article, and then they have to signup. Like many newspapers has now.

This feature on UM, allows me to restrict access completely.
What I to do, is tease the users into asking for access and signing up.
What would I need to make this happen?

Rgds