Redmine

We typically have two projects - an external project and internal project. When a client reports an issue it gets reported in external project. We then create one or more corresponding items in the internal project and relate it to external issue. I am looking for a way to do 1 of the following

1. Update the status on the external issue based on status changes on the internal
2. If that is not feasible, a way to create a cusotm query on external that shows all issues where the related internal issues have been "Closed"

Thanks