customize blog plugin

I have a plugin and would like to override the  save.php action located in the blog module at: 


Can you override this action in the same manner as overriding a core action since it's part of a module?  Register the action in my start.php with path:

/var/www/html/mod/my-plugin/mod/blog/actions/blog/save.php?  I don't want to recreate the blog just update that action.