Just some more questions to clarify,
1. Need to understand more of your existing website applications, are those all in HTML and the backend is Perl?
2. What kind of cookies need to be put into user browsers side after user click the 'accept' button in the pop up?
3. Is blocking Google analytics cookies also a formal requirement for this? Which pages are using Google analytics?
And I am experienced in website projects using HTML, Javascript and Perl, including commerce websites and other commercial applications, etc.