I haven't found anything on the topic in the Internet. The only line from
.mc/ini that looks related to the question is
keymap=mc.keymap but I have no idea what to do with it.
Okiedokie... lets see
8th section... is that possible? Lets look
man mc (scroll,scroll,scroll)
Now edit the key mappings as you like and save ~/.config/mc/mc.keymap when done
For more info, read the Keys (man mc) section and the three sections following that.