are you talking about the stacking method??? There is a free software called CombineZP from Alan Hadley. http://alan-hadley.software.informer.com
It is for PC and quite simple. All you need to do is get images with different focus distance from your image (all with same length and height) and upload them to CombineZP
here is a short tutorial
have fun and let me know how it works
cheers
Ronny