Permissions over a folder

Hi everybody
I have a site with Plone 4.3.7
I need to set permissions over a folder, so that every user can create an object in it, but he can only see his objects when he looks in the folder.
UserA add OBJA0 to FolderX
UserA add OBJA1 to FolderX
UserB add OBJB0 to FolderX
When UserA opens FolderX, he sees only
When UserB opens FolderX, he sees only

You need to create a custom workflow for the objects inside the folder. This is a complex topic, but can be done through the web. A good starting point is
Your new workflow must allow view permission only to owner role.