Is there a way to get cross hairs on the video screen element. I would like to use a video window with my USB microscope for optical xy zeroing.

Yes, you can add an image in the 'Image' property of the video control. See attached

Thanks that was a little tricky but it worked.
For anyone else who needs this, here is what I did. I looked at the size in pixels of my video window in the Mach4 screen and created a grayscale image of a centered black cross with a transparent background in photoshop. Saved it as a png (attached). Changed the extension on my screen set file extension to .zip and then added the cross hair image to the images file in the new zip folder. Changed the extension back to .set. I could then go into the screen editor and add this image to the video screen element.  Since the cross may not be exactly centered, I recalibrated my offsets to the tool center as a final step. The cross overlay was smaller then the video image so controlling the number of pixels may not be that important.
I am sure there are other ways to do this, but this worked for me. It takes about 20 incremental .01" jogs for my microscope camera to traverse a drywall screw head, and the cross makes it easy to see the center and maintain consistent offsets, so I am happy with the results.

When you're in the screen editor you can just go to Screen>Manage Images when you want to add new images

Thanks, Mach4 has a lot of things to discover