For a handful of specific pages, I prefer to use the <meta name="robots" content="noindex,follow"> tag. You can use robots.txt to accomplish the same thing, but I prefer not to clutter it up w/ single pages. But it's a personal preference. Up to you.
Not sure why the page being dynamic prevents you from doing this unless you have no way in your CMS or DB to specify the value for the robots meta tag for each page on your site. We just implemented a CMS system at work, and I made sure that every leaf or branch item type representing a page had a field on it where I can indicate the value. It defaults to "index,follow" but I can select any value from the dropdown.