That depends on the program. In some programs the keyboard shortcuts can be changed in the preferences while in others t are just hard-coded in and you can’t change them unless you tinker with the source code.
You can find a list of all program shortcuts (with a help of the KeyboardShortcuts and ProgramShortcuts programs) on aircrew#6255. This page lists them in the order I use them. If they are not listed there, please tell me. [1] — When you run an X client in an X11 terminal you will have to move the mouse to the right on the X server to see the program shortcuts — you need them to use the program's menus. [2] — You can change the KeyboardShortcuts and ProgramShortcuts programs in the Aircrew#X11#Configure menu at the start of aircrew. You might want to disable the “Auto add shortcuts” option in aircrew.RC. [3] — You can set up the “Save program shortcuts to.Mike files” option in ProgramShortcuts (if the program doesn't have a separate.Mike or .cone file, and you don't want to put it in the Marc folder, you can do.