You might also want to try your school career center. I know that the company I work for mostly does its intern recruiting this way. I'm actually sitting next to a PhD in Operation Research intern and this week is his last. So as Yan He said, you're a bit late in the game. :(
You can also use regular expressions for this sort of things. It's pretty powerful and can be used to match very complicated patterns.
Regular expression - Wikipedia, the free encyclopedia
So for your case, the regex would be something like: .*[6-9][5-9].*
If you have a unix terminal, you...