You can use create subscription with the without materialization clause to activate a subscription when materialization has already occurred..
When creating a subscription with the without materialization clause, Replication Server logs in to the primary Replication Server as the user creating the subscription. The user who executes create subscription must have the same login and password at the primary and replicate Replication Servers.
You can also use create subscription with the without materialization clause to subscribe to function replication definitions.