I have a report with multiple columns that need to be concatenated into a
single cell for import into a CRM. I can't just concatenate a range because
I need to insert line breaks and punctuation between the various columns. I
also need to convert into a CSV before importing.

Because there are so many columns (only about 20), I have to break up the
concatenate function into 3 separate columns, then concatenate the resulting
3 columns. That's where I get the error:
"The text string you entered is too long. Reduce the
number of characters used or cancel the entry"

Even though I get the error, the final cell seems to work, but when I save
as a CSV file for import into my CRM, the cell gets truncated to only 256
characters or so. I've tried copying and pasting the values before
converting to CSV, but that didn't help either.

I've had this problem with Excel 2003 and Excel 2007.