I made a quick project a while back to demonstrate how to do this. Mask so just min:sec appear. In addition, in this project I make them run faster than normal for a timelapse effect and the counter moves along a timeline. You can easily remove the speed change and animation.

Here is a demo:

Here is the PPRO2 project file to recreate it:

(right click on the prproj file link and do a save as. Open it in PPRO2. No external files or graphics needed.)

Courtesy of