You should be able to send a message to any Layer Zero endpoint on any chain and have it received on Rinkeby. Example is in the sendToRinkeby script in the Optimism Kovan folder.
The example sends 1 of 3 different types of payloads from Optimism Kovan and is received by the contract on Rinkeby and updates the state accordingly.
MultiReceiverSGV3
Implements sgReceive as well as lzReceive
Contracts takes in a payload for both lzReceive and sgReceive, as well as tokens for sgReceive
Executes logic based on which payload is sent and if it's from sg or lz