It’s a hard problem to solve. Would this answer be any more helpful?
I know it’s not a perfect solution, but it is a start.
P.S. I’m working with some others to solve the bigger problem with a plan to release as part of a GPL-licensed product. We are looking for people who have this need to help us define the requirements. If you are interested in detailing your specific needs and letting me or others ask you some more detailed questions please contact me via the email in my profile. We just don’t want to build something and then find out it’s not what people want or need.