block adjustment

For lack of a better way to describe what I need I will use block
adjustment. My client has asked if I can mimic the way word adjusts a
paragraph to expand words and spaces to create a block of text. That both
sides would be flat on the sides. 

I have looked at the faq's and several pages referencing css and have
found that the only thing I can manipulate is the line height not the
width. Has anyone discussed this before? Under what heading so that I can
find it in the archives? If not, has anyone tried to figure out how to
accomplish this?

Sincerely,
F. Havas
ches@io.com