Both suggestions so far are mostly correct.
The 1761-NET-ENI cannot be an I/O adapter for a ControlLogix system, in which you would place it in the I/O tree and automatically poll data from it as though it was an EtherNet/IP slave device.
Instead, you will send MSG instructions from the ControlLogix to the 1761-NET-ENI, which will translate them to DF1 Full Duplex protocol and forward them to the MicroLogix.
There is no need to use the PLC/SLC Mapping feature in RSLogix 5000 unless you choose the more difficult method of initiating the MSG instructions from the MicroLogix side.
There are numerous examples of sending MSG instructions over Ethernet from a ControlLogix to a MicroLogix controller in the RA Knowledgebase and in various User Manuals.