I think you should have done more research. HTML::Template supports using HTML comments for your template tags. TT has configurable tags and supports in-line Perl. Mason has configurable tags. Other options like Petal let you work directly on valid HTML documents without even adding comments.

In short, there was no need to do this. However, your real motivation seems to be something about the difficulty of using CPAN modules at your job. I'd suggest working on fixing that, rather than duplicating solutions for problems as well-covered as templating.