I thought "this guy" owned a term-paper selling web site when I first read the question. :)
To the OP: As others have said, this problem is HARD! You can't really tackle this without AI knowledge, I don't care what "this guy" thinks. In fact, there is probably a Turing award out there if you can solve NLP of English idioms and cliches and such -- especially when coupled with voice recoginition and translation systems. However, I don't think you or "this guy" are going to get it any time soon.
Pick up a copy of Russell & Norvig, or equivalent, and begin to learn what "hard problems" in AI mean versus what most other folks consider "hard problems". AI is a whole 'nother animal. And it's still a very loose science (overhyped too -- in that few understand what it actually is), with a lot of room for ground-breaking. Perl (due to functional constructs, etc) isn't a bad language for it at all, however.