Hi,
When a Subflow is called, the END step within the called subflow provides the return back to the parent script.
Following is from Cisco CRA Editor Step Reference Guide (under Call Subflow Step)
http://www.cisco.com/univercd/cc/td/doc/product/voice/sw_ap_to/apps_3_5/english/admn_app/step.pdf
If the script was originally loaded from disk, the subflow script must reside in the same folder as the script that calls it. If the script was loaded from the Repository, then the subflow must also reside in the Repository.
Hope it helps.
Regards
Venkat