You can not register the lines of the phone . Phone registers to the server. If you need the lines of the phone to use different gateway than you can use partiton/CSS . you need to create an ICT or SIP trunk between your two clusters and than create a route pattern, such that it will send the call through the ICT and than other server can route it through its gateway.
NOTE: for this kind of setup you would be using your WAN bandwidth so configure it to use G729
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.