Hi Matija,
Well, if the image URLs are stored in a custom field, then you can use the advanced title and content field features to alter the output.
For programmatical changes, I suggest using the asp_results hook – there you can programmatically fetch the images needed, and add an output HTML to the $r->content field.
For even more specific changes use the results templating feature as well, that gives you more control of the actual output.