Apple - How can I select files in Midnight Commander on a MacBook Pro?

Ctrl-T is standard hotkey for file selection — http://linux.die.net/man/1/mc.

As for switch/add/substract, just type shift-8 for *, shift-= for + and - for minus.

All this works in MC out of the box.

Control+T will select files:

http://austringer.net/wp/index.php/2008/06/07/mac-os-x-and-midnight-commander-the-missing-insert-key/

For those like me who were drawn here by a Google search based on the title of the question (not relating to Midnight Commander), I still haven't found a great solution. However, for Word processors (a common usage of needing to find the "insert" key to toggle Insert/Overwrite mode), you should be able to click the text that says "INSRT" or "OVER"/"OVWT" in the status bar on the bottom of the Word Processor to change modes, as detailed here for Open Office. Not awesome, but at least functional.

If neither Midnight Commander nor a Word Processor drew you here, then...good luck in your quest!