Do I want modules? If not, what?

I'm trying to modularise out web-site, it's mostly CGI (perl) apart from two or three static HTML pages. What I want is a perl script which calls a header, top-bar navigation, left panel, page body, right panel. And each of those sections to be separate perl programs which can be edited independantly of the main 'index.cgi'. It is a requirement that I can