I thank you gentlemen for the very helpful advice. Inserting the following worked perfectly: Key0=0x53,c,"CTRL S". I now have the tube cyclers using W for forward tubes and E for the stern tubes, and can Emergency Surface with the above CTRL S.
Captain Robbins, when you suggest using the TMO keyboard, with which I am the most familiar, is that simply a matter of replacing the stock or whatever data/cfg/commands file with the TMO data/cfg/commands file? Or is there a separate file for the TMO keyboard?