What happens when you try it? Error number?
I think by default a list box entry will be 1 line. But, there's a lot of creativity out there, so someone may have customization that would apply.
If I had a longer text string say 78 characters and wanted to display it in several "lines", say line length 23 chars, an approach might be:
-dim a tmpstring
-take the text string.
-starting in position 23 look for space
--if found, then put the 23 chars to my tmpstring and add a vbcrlf
then start checking chars 24--to 46,
--if not found,then start working from 23 back(eg 22,21...) until you find a space (natural break so to speak)
-continue that process until the initial string has been processed.
move the tmpString to the output.
I don't know if this will work with a list box or not (it's just how you might approach converting a long string into multiple short strings on different "lines".
Good luck.