IPv6 proxy

[ProfessorMelon]

I need to set proxy for Wi-Fi connection to IPv6 address that has no corresponding domain name. When I type this address in the proxy name field (with or without brackets), the save button is disabled. I guess I can root the phone, edit the hosts file and set proxy by host name, but I hope there is some other solution. Any ideas?
Android 4.1.1, Samsung Galaxy S3.

Thanks!