This is for John, and anybody else who may be interested.
Now that I've had time to think clearly. Yes, you can enter two or more
lines in a header by using alt-enter. That turns on text wrap for that cell,
and it does not seem to damage the cells below.
My problem was that your wording seemed to indicate that you wanted to put
more than one type of data in a column. I think you used something like
home phone, cell phone, etc. as a header. In my opinion, that would be
inappropriate. It's much better to have a column for home phone and another
column for cell phone.
If what you really meant was a way to include explanatory information, then
it is certainly possible to use more than one line in a header. Example:
Home phone, and below it "Please include area code"
I hope this helps, and my apology for perhaps not understanding what you