How to create custom ADM file: http://support.microsoft.com/kb/225087

Script to convert registry keys to ADM or ADMX: http://gallery.technet.microsoft.com/ScriptCenter/en-us/8c703a2e-4685-4093-a1fc-dec107c53d13

ADM Template editor:

http://www.brothersoft.com/adm-template-editor-download-229531.html

http://www.sysprosoft.com/adm_summary.shtml