How do I create a Hard Space? That is to say, a space that prevents wrap-around, ensuring the two words either side of the space are always together on the same line.

I need this to ensure an ellipsis doesn't get split up. (i.e. <full stop><hard space><full stop><hard space><full stop>)

In WordPerfect it is the spacebar combined with one of Shift-Ctrl-Alt (I can't remember which). None of those combinations works for me in Word.