For information on call forwarding, refer to the following:
I don't believe there is a way to setup call forwarding without access to a working device on that number. I've never seen any capability like that for any phone, wireless or landline. To me it also seems more like a security risk overall. By making it be done by the device it is forwarding from it ensures that the owner wants it to be done (if the phone is stolen, then they have other considerations anyways, like turning it off entirely). Forwarding can accrue sharges at a fairly high rate if you get a lot of calls while using unconditional call forwarding.
Check out a fun infographic that teaches you how to increase storage, enhance security, improve battery life and clean your device.