I am attempting to copy a site built in Oracle Portal including all documents
published on the site. 

The links to a lot of these PDF's utilise Oracle GUID's and take the form of 
<http://hostname/pls/portal/url/item/99BEAC025A9A3176E0406F0A6F1F1282>

When I check the mirrored site, these links still point at the original site.
I need HTTrack to download the file and amend the link to point at the local
version stored with the rest of the archived site.