Filling every single line of the left-justified text with a specif

[MMART]

To protect a printed legal documents we need to fill every single line of the
left justified text with a specified character or a repeated short string of
characters including empy lines.
What are the options and what is the most easiest way to do it in Word 2003
(an later versions).
MMART

 

[MMART]

The problem can be extended to the right justified or centered text and to
the last line of the fully justified paragraph, headers and footers.