If I insert a line break (ALT+ENTER) in the middle of text in, say, cell A1
then the text breaks where expected. If I then set cell B1 =A2 the text
doesn't break and there is a "character" where the break should occur
indicating that there is a non-graphic character there. In both cells the
line break is present because the CODE function returns a 10 (which is the
ASCII code for a line break) for the character.

How do I get the line break in cell B1 to do what it is supposed to do?