NX 12 | SW 2017 | Creo 4 | TcUA 11.4
If TC_ROOT and TC_DATA is available in your environment you can use plmxml_import. The password can be encrypted in a passwordfile, then run the command with option -pf. cron job or windows scheduler can be used to run the job periodically.
With some programming import can be done with Teamcenter SOA.