I want to look up state-ids in subflows from main-flow and transition to that state.

Main flow which has many subflows which are executed based on user-selection in main flow.
When user exits (he can from any page of whole flow),saves the current-state of user in subflow.
This state-id/state could be in main-flow or in any of subflow.
Next time, user logs and db-calls fetches to get state-id where we want to traverse now.

I am able to go anywhere in main-flow but fails if state-id is from subflow.
I know its impossible to navigate to subflow without going through start-state

how can i implement this functionality?Any other ideas?