How do I convert UNIX flastmod statement into PHP for WP 3.4.2?

In my file I have the following:
Updated <!--#config timefmt="%d %B %Y" --><!--#flastmod file="doc_company_resources"-->
This doesn’t work in WordPress. How do I convert it to PHP to get the date of a remote file?

What I want to have in my page is a
link to page …/doc_company_resources Updated 6 November 2012