Select The necessary rows or columns and go to Data | Group and Outline |
Group to do this manually.
To extend your Subtotals analogy, you should group the rows or columns
similarly to how they are done with subototals.

You'll likely have to play a little to get it to work the way you want.
Here's a reasonable explanation with screenshots:
http://cma.zdnet.com/guides/qa_excel...22001_007.html

tj

"Jeff" wrote:

Hello,

I am looking for a way to add the outlining qualities of the sub-total
function without actually having subtotals. I have recently come across a
spreadsheet that has the left margin set up with the outlineing feature as
if the subtotal function was run, but there are no actual subtotals. The
document is a site map and each of the columns indicate the outline level.
For example
Level 1 Level 2 Level 3
Alpha
Bravo
bravo-a
bravo-b
Charlie
Charlie-a
Charlie-c
Charlie-c-1
Charlie-c-2


If I click on the level one filter in the outline bar, only the level one
items appear, but I can select the individual areas to explode (I could
click on the "+" button next to Charlie to see the detail of Level 2, then
click on "+" next to Charlie-c to see that detail).