How to put a dotted line stroke on a vector shape using Photoshop

I've created a simple vector pennant type banner using Photoshop. I'd like to put a stroke on the banner with dashed lines approximately 3 pixels in from the edges of the shape. I know I can add a stroke to the shape and that looks fine, but I want to position the stroke so that there is a space of about 3 pixels between the edge of the pennant and the stroke. Is there a way to do that using Photoshop?