If I understand your question correctly, the block that you're
using in your page region is either indexing pages or has a Data
Definition file chooser and your trying to create a link to one of
the indexed or chosen assets.
If so, take a look at the <link> element
under the "Indexed
Asset Content". This will only work, however, if the indexed or
chosen asset is in a Site. It's not possible to create a usable
link from a Site to an asest in the Global area because there's no
Site URL to use for the link.