I was using APPC connections back in 1990-1991 so they pre-date CICS TS by a number of years. AFAIK, the APPC connection capability is part of the base CICS package and does not require anything but setting up the connections with the external servers. Since the connection is one-to-one, you will need to have some set up done on the external servers to be able to connect your 1.1.1 region to them.
The site support group must be involved -- there is a need for VTAM settings to match on both sides, along with other pieces such as CICS region names. Why not copy the existing APPC definitions and just change them for the new region?