Search metatag script

I'm pretty new to PHP and have no programming background, so I wanted to ask what would be the best way to approach this script. A client will develop a set of keywords which we will post on a Keyword Index page (probably 50+). He will then designate which of 25 product pages to apply these keywords to, and the relevant ones will be placed in the keywords metatag (no other words will be included there). The script I want to write will search only the keywords metatag and will return a list of links to the relevant pages. Sounds simple enough, right? I tried some free scripts that would search the whole site, but customizing them for this function seemed like reinventing the wheel (and a rather complex wheel at that). Does this sound like something a newbie could do? If so, any general guidelines/advice would be greatly appreciated.