See the menu "Scripts"; after copying new script files, you may need to call "Recompile scripts" in this menu. The scripts usually contain an "Init" section, which builds menus and submenus in the "Scripts" menu, optionally also shortcuts can be set here.
-- <http://forum.pspad.com/read.php?2,43562,43563> PSPad freeware editor http://www.pspad.com
