I'm posting this mostly to let others know about my findings.  If anyone knows a way around this, please, post a reply!

As it turns out, my research shows that a format-1 accept (even in gui) can be controlled by the keystroke variable, so you can set up to get an exception value.  However, if you use an ENTRY-FIELD control, the left/right keys are trapped by windows and the field cannot be exited (just like the manual says).   Note: I'm just trying to get one character, including any function/movement keys.

I cannot use the W$GETC (won't work for my application).  I've been using the format-1 accept, but I've been running into issues where the active window does not get processed the same when not using the entry-field, even though I use the SET I-O WINDOW to xxx, before doing the accept.   As a result, in my application, clicking the minimize button triggers some handling which does a switch to the main window, check if any mouse movement using format 1 accept, then switch back to the floating window where the accept is taking place.  But when we restore the application, the floating window does not display, the accept looks like it is in the main window we switched to temporarily.   Oddly, if the field times out, something resets in the background and my active window issues go away and the floating windows re-appear.   I tried switching to using an ENTRY-FIELD, and the active window issues go away, and the windows display correctly when we restore the application, but the left/right arrow cannot be captured, and since this function needs character-by-character response, I cannot use that.   My solution?  Reduce the timeout to about 3 seconds so the windows re-appear fairly quickly most of the time.  It's thin client over the internet so a smaller timeout is in-efficient.