In version 3 there is the export button that allows the exporting of the SCOM ID. I am in the process of moving my dashboards and I have noticed that the ‘export’ button is not available.
This is a bug that’s been logged with the support desk. Drop them a line and they will add you to the dev ticket so you can be notified once it’s fixed.
As a workaround, you can find the export button on the alert list scope.