I'd like to select those four images, type in the caption once (using code replacement), and then have it apply to all of those images. Right now I'm having to copy and paste which is just time wasting drudgery. Is there any way to to this easily and quickly in Photo Mechanic?
Unless I have misunderstood, can you not achieve what you want with Find and Replace? Use the Metadata Template to set the caption for your entire batch of images and copy the text to the clipboard; then select the limited number you want to change, paste the text from the clipboard into the Find field of Find and Replace, type the replacement caption into the Replace field, then apply to the selected images, which is a one click operation. Would this not achieve what you are trying to do?
I do not often use code replacement, but if I have, for example, a series of pictures of a species of bird which I need to caption, usually one but a few instances of two, I will use the Metadata Template to set the caption of the entire collection of images to "xyz"; then select the small number of images that have two birds and run Find and Replace to replace the xyz caption with the caption applicable to two birds; then select all the images (which by now only have a caption of "xyz" if there is only one bird, so it is not necessary to select the sub-set of either one or two birds) and run Find and Replace again to find "xyz" with the Replace field containing the caption applicable to the images which only have one bird. It is thus necessary to select the limited number of images with two birds only once, and their captions can be set without having to copy and paste to them individually.
Hope this helps, and apologies if I have misunderstood the original requirement.
Graham