After Effects :: Capture A Drawn / Painted Stroke?

This isn't directly about After Effects, but the end result is something I will use with After Effects...so here goes:
 
I'm looking for a way to use Photoshop or Corel Painter to "draw" an alphabet, while capturing the strokes as they are done in real time. I don't want to see the application's screen cursor. I also don't want to take the completed letter(s) and reveal them with a matte. This doesn't look real, and is also problematic where lines intersect. So, I'm thinking there must be a way to do a video screen capture, but I'm not familiar with applications that do this.
 
Here's an example of what I'd like to recreate: [URL]
 
This example appears to have been done with real media, ink and brush. I'm guessing the artist may have shot video from behind a translucent substrate as the letters were drawn, and then flipped the video (so the letters weren't backwards). It looks great, but I'm hoping there is a way to mimic this effect on my Mac.