Automate merging images to different files.

Hello, 

I am trying to automate a card signing process so that someone may be able to write a note to a recipient in advance on a separate page of paper, and then we can scan them and add them to different cards. This would ideally be applicable in a few ways; it can be a person writing a few notes that can be given out to different recipients, or it can be unique notes to unique persons. The cards would be in the hundreds or thousands, so we wouldn't want to manually export each handwritten note to each card. I've used Excel before to merge texts like addresses onto the front of envelopes, but we'd want to do it with images for a holiday card so a person's note doesn't have to be hand-written for a large stack of cards. 

I'd ideally want to control over the precise location of where the image is placed on a card, and I would want control over the naming convention so we could make a lot of copies. 

Please let me know if this makes sense and if you have any suggestions. Thanks!