Wrapping all links with custom tracking tags

We have links to PDF files posted throughout our site that we’d like to track using a custom JavaScript tracking tag, i.e. [a href=”(javascript: cxDownload(‘http://www.sitename.com/document.pdf’, ‘Document Name’);”]. I’m trying to think if there’s a programmatic way to do this, rather than going through nearly 1,000 pages and manually modifying every single link. Any ideas?