breaking a long name to multiple line

Hi All,
we have a requirement as follows:
for ex:  fullname=firstname+middle+lastname

if the fullname having more then 20 characters, fullname should be broken down such that only 20 characters should appear in a line(as envelop window can accommodate only first 20 characters),
remaining characters should be displayed on the next line.
How to achieve this at bi publisher report level.

any help will be appreciated.

thanks in advance.

Regards,
Pkatti