@david I don’t understand why you’re saying this is impossible. This issue has been addressed on this forum previously and it was indicated by several developers at the time that this sort of functionality would be able to work, and that it would be integrated into the core. It appears that it’s still not working after 3 years, however. I’m not sure why this should be an impossible feature.
See the following threads where this same sort of issue was discussed and it was said that this functionality would be able to work: