When I am working within a table cell, I want the horizontal ruler to
show measurements relative to the cell border of the current cell (and
not relative to the page margins, as is default). So in every column
the ruler has to start at 0 again. I don’t know how to achieve this. I
can vaguely remember it is possible, I think by using a certain
keystroke combination.
In the Word 2003 help file the is a picture of a ruler of the type
that I want: please view the ruler in the Help topic “Indent text or
numbers in a table cell”.

How do I get my ruler to look this way?

(I am using Word 2003.)