Open Attachment via personalization

Hi,

We have a requirement wherein we want that if there is an attachment at the item master level, then when we create a po line for that item, there should be an option available to open the attachment linked with that item.

We are ok to  have a "Open attachment" special menu in the form and want that when the user clicks on that menu, the associated attachment opens up. If the attachment is of type file, then we should get a prompt to open that file, just as we get when we click on open document button in the seeded attachment form of apps.