It is 6999 that you will need to open up for CCX Editor to work over VPN. Refer below for complete Port Utilization table on UCCX:
http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/crs/express_10_6/maintain_and_operate/guide/UCCX_BK_UAC60444_00_uccx-operations-guide-106/UCCX_BK_UAC60444_00_uccx-operations-guide-106_appendix_0101.html
Regards
Deepak