How do I add non-breaking space in text?

In French language there is always a space before exclamation or question mark. So I would like to replace it with a non-breaking space to avoid situations when it's wrapped to the next line like this:

I tried copy-pasting different whitespace characters, using JS code "String.fromCharCode(160)", but nothing works. Looks like all whitespace characters are replaced with a regular space.

Is there any solution?