(I know that Opera isn't "officially" supported, but...)
Since v11 Opera is using plug-ins as well but they seem to have other format than Firefox or Chrome. If I place nplansweepershellexec.dll in %localappdata%\Opera\Opera\widgets nothing happens. Ok, it's logical 🙂
However if I place nplansweepershellexec.dll in %ProgramFiles%\Opera\program\plugins\ and restart Opera, the browser is partially able to work with custom actions. For example, any actions based on cmd and/or console commands will execute without a problem. More complicated actions with paths, parameters etc cannot be started with "File not found". Surely in IE all is working.
Is there a chance that the plug-in will be adapt for the Opera browser? I can offer any help with testing.
Many thanks in advance.