You should understand first, what you know by now:

• HTML::Template returns just some text, right?
• And that text could fit inside one of any other H-T field, ok?

So, instead of using use or require, just study how you could 'inherit' classes that hold H-Ts in it. Every class should handle one level or directory of your page (sort of). When you want to go deeper in some level, you call another class that inherits all the other values and returns the text to put inside an H-T field from the upper level.

I am also planning to manage a site by this way.