If that's what you are referring to, this is possible by slighty rubbing the side of your thumb (of your picking hand) on the string as you play the note. By just barely touching the string, the guitar should produce an harmonic like sound. Now once you're able to do a pinched harmonic, the only thing left to do is to do a normal bend like you would do with any regular note.
Harmonic bends can also be produce by using a guitar that has a wammy bar. In that case you could play a natural harmonic and then use the wammy bar to bend it up or down.
Here's a few lesson on harmonics and the different types of harmonics you can make.
http://www.guitartricks.com/lesson.php?input=4227&s_id=35
http://www.guitartricks.com/lesson.php?input=2397
http://www.guitartricks.com/lesson.php?input=10224&s_id=267