Since I'm not using the clipboard now, Ivan's Ctrl+C is just what I need. Thanks! Too bad it took years and nobody from Microsoft suggesting it.
One imagines a meeting in Microsoft with some main Theory of Programming dude saying "I discovered we left focus on cells that don't actually have system focus. I filed a ticket to correct this discrepancy - please have it fixed and tested before the next release!!". Others at the meeting: "were people complaining?" "did we check what other tools do?" "did we ask users how they might use focus when also using other tools at the same time?" "let's understand this before changing"
Of course if those questions even came up at MS, they seem to get ignored because the bureaucracy seems to be about adding new "stuff" and not improving the user experience. Forcing people to use the same Excel frame for multiple spreadsheets comes to mind as a change that reflects a serious disconnect from actual users.
The dumbest thing is to say "well, you could change the color of the highlighted cells each time that you switch to another application - and then restore the color when done". Better might be "oops, so sorry messing that up. We expect to have this fixed with a new KB. Until then, use Ctrl C to hold focus box". Man, that kind of response in the first reply from MS would have eliminated all the struggles and improved the product quality for the masses. Excellent possible response for the cost * number of users. Next time....