Samsung remote - Cec mapping

Hi, my Samsung remote works beautifully with my little pie 2. All I would like to add is say holding down one button longer gives me a list option I.e more info etc. How do I do this with a remote already working via Cec and has had no setup carried out by myself?

CEC will provide no support of long-press function.

Okay so begs the question, how do you set a certain key to do this action?

Find remote control setup and look for context menu setup.