I've been copying my old post into word and doing a replace on the whole URL minus the base photo name. To make this work, you have to use the same base name for your photos. And for me, I had been keeping all of my photos in separate sub-directories so that I didn't get too confused. Since Coppermine only supports one level of folders for your images, I used a free tool called "Bulk Rename Utility" and it helped me quickly append the subdirectory name to all my JPGs.
And I in my search/replace, I added the directory name in too.
To make it a little easier I wrote a macro/script to do the search/replace. I'd be happy to share it with people, but it is really rather quick and dirty. And you'll need to change the hard coded coppermine URL to your gallery, not mine
But if it would be helpful to anyone, I'm happy to share.
Kim