I indeed agree to the fact its do'able, as there are files here on Kayssplace that have lethys, khazars and nemessis icon changed, these also change the icons of the CCPs in skirmish games.
After sifting trough EVERYTHING on kayss, here I found the icons!
http://www.bwfiles.com/files/index.php?action=file&id=836
http://www.bwfiles.com/files/index.php?action=file&id=832
http://www.bwfiles.com/files/index.php?action=file&id=833
http://www.bwfiles.com/files/index.php?action=file&id=834
http://www.bwfiles.com/files/index.php?action=file&id=835
Patrick Selter has alot of files sent to here.. O_O
Anyway, you have the files now, so you can look to what file it is that is edited, and perhaps how he unpacked/packed it!