Overlay a static image on the home page slider

I am trying to determine how to "overlay/layer/stack" a transparent logo png over the images in the home page slider, but cannot find any information on what is involved in this modification. Specifically, I have a logo in the form of a png image with a transparent alpha channel. I would like it to be centered in the home page slider and remain static as the slider images revolve beneath it. So, the logo remains in place but the slider images change as normal. Any assistance in what I can do with e CSS to make this change would be very much appreciated.