Making a linked image an album icon.

[GTO400hp]

Hi, I've set up a category called Subjects and within the category are different albums according to the subject of the pictures ie there is an Abstract album, a landscape album, a Portrait album etc setup.  Using keywords when users upload an image into one of their own albums their image is also associated with one of these albums in the Subject category.  However, the album icon for these albums  within the "subject" category are simply the default icon for coppermine.  I would like to have the album icon for each album be a picture linked to the album, how can I do this?  No images are actually in the albums, they are just linked to it from a user album, so when I choose edit files in the Album Properties no images actually show up.

Thanks for your time.