Thanks for the ideas.
The camera (Canon PowerShot S70) is controlled through a USB cable. I have thought about opening up a cable and trying to hardwire a switch, though I am fearful of losing the other functions that the cable/software provide.
After doing some more research, it looks like I can create a batch file in PSRemote that can trigger the camera, rename the image, save the images in a specified folder, etc. Now I need to research how to run batch files with the Mach3 software and hopefully Mach3 and PSRemote can work together to solve this problem. I will keep you posted.
If not, the solenoid is a fantastic idea. Thanks.
buck