G'day fair,

Welcome to the Monastery.

Your first foray here has drawn the ire of a number of monks. I can see you've garnered a number of downvotes. Anything along the lines of "I want help", "Show me code", and such like, will get similar responses to what you've received here.

We're more than happy to help anyone who's shown some effort; however, this is not a code writing service.

"I have no skill in PERL."

None of us left the womb with any skill in Perl. Like other skills, it requires learning and practice. By the way, the language is called Perl; the program to run Perl programs is perl (possibly with an extension such as .exe depending on the OS); "PERL" is not a thing.

I suggest you start with "perlintro: Perl introduction for beginners". Bookmark the "online documentation". Take a look at its Tutorials section; in particular, the FAQ links.

From the brief glimpse you've given of the problem domain, it seems as if you're looking for a recursive descent parser. Maybe take a look at Parse::RecDescent (and possibly Parse::RecDescent::FAQ although I have no experience with this module/document) or Marpa::R2.