you gotta make a brush by dragging out a rectangle and saving it as a brush. then make a path of where you want the dashed stroke to be. then, with the brush selected, go into the brushes pallette and click on brush tip shape and mess with the spacing until it looks right. then in the paths pallete, with the brush selected, click on the Stroke Path with Brush. this is a rough idea of how to do it, but just mess around a little and you should get it, it's close enough.