You can achieve this by using your own keyboard (one which has extra programmable keys) or by using Karabiner (or AutoHotKey or …) to make life easier for you.

You can achieve this by using your own keyboard (one which has extra programmable keys) or by using Karabiner (or AutoHotKey or …) to make life easier for you. For instance, if you hold C down it could interpret that as Command-C.