Excel works very well. You can set up the penalty times and miss times. You enter the shooters raw time, numbers of penalties and misses and it will add it up to a net time for the stage and you can set it to add the stages for you and give an overall time.
At the end of the match, with a couple of clicks, you can have it sort each class by time.
If you have a printer set up you can enter in the shooters names and print score sheets for the stages.
My wife set it up for the first CCC match and we have used it when I was able to attend and bring my computer.