No. Forwarding phones is not something over which On Call Central, or indeed any answering service, has control. If you think about it, it would be a major security issue if any 3rd party had the ability to take control of someone's phone system and force it to route traffic to whatever destination they choose. Forwarding phones, therefore, is entirely dependent on your office's phone system. Some office phone systems might have web-based administrative interfaces that you could use to forward phones to On Call Central, but it will be up to you to use that interface to forward your phones to On Call Central.