I've never used or even looked at Powerlaunch before, but according to the "Powerlaunch" section on the "Powerlaunch: Documentation" page, the software looks for its configuration files--both .conf and .glade--in "/home/user/.powerlaunch" and "/etc/powerlaunch", in that order. Also, by default, the file for which it looks is "powerlaunch.conf". There's an implication that there's a way to get fancy and specify either alternate or additional configuration files, but I didn't notice how to do that at a glance.