Re: Transperent background
You could save a rectangular bmp which is that occupied by the clock... When you need to refresh it, you can erase the clock background with the original image partial bitmap (overriding the CStatic OnEraseBkgnd() ), and then superpose the new clock.
Sorry, can't think anything more right now...
Re: Transperent background
If, by "one big mess", you mean the numbers continue to appear on top of each other until they are unreadable, then, try setting the static control to blanks before updating the time.