Actually, I found a way to use Keyboard Maestro to reprogram ALL the user keys including not only 1-5 but also Home, Calculator,
Applications, etc. Simply user the trigger "This device key", then click on any key on the keyboard and it will be accepted.
I would post a screen shot of how simple this is but even the least quality I can generate greatly exceeds the allowed message limit. Strange. My Keyboard Maestro macros to launch an app on my Mac contains but a single command in addition to the trigger. Namely, "Open application-name".