maltris on "Only show posts depending on the date given in a custom field"

I have a custom field with a german style date written in it:

15.10.2014

I want to exclude the post with this custom fields value since its 16.10.2014. Before, the post should be normally shown.

Now there is a special requirement. The post should be still accessible. But it should be removed from the search results and categorys etc.

My brain is kind of laggy now, so please give me a kickstart on this. Maybe someone already did something like this?