I've made a little program name EQNicePatcher.
Juste put *.png pictures in the EQNicePatcher directory and it automaticly change the picture (randomly) and launch Everquest or other third party application.
EQNicePatcher duplicate \skins\default directory to prevent any modification with futur EQ Patches, rename XML file and include <skin> tag.
No installation need, juste edit the .INI file to indicate your EQ installation directory, pout png picture and launch EQNicePatcher... It's all
Program can be downlad
here