I agree with Andrei that uidoc.Import is your best choice in this case.
However, I disagree that you have to save
the document to make back-end changes to appear. You can close and reopen without saving. See the Update rich text tip
. I don't recommend that for this
application, but it's good to know that it's possible.
Or, if you have a limited set of images, you can make them image resources, and use a formula to display the appropriate one by just refreshing the window.