The main thing that will help you is the shortoutput runtime parameter. To quote the documentation:
When running multichaind, this only show the node address (if connecting was successful) or an address in the wallet (if connect permissions must be granted by another node). This is useful for building automated deployment scripts.
If you want to pregenerate private keys for the nodes in the network, the initprivkey parameter can also help you, by telling new nodes to start with a specific private key (and its corresponding address) instead of randomly generating their own.
