HELP REQUEST: How to 'Protect' Certain Cells from Changes?

Greetings!

THE GOAL:
I want to protect several ranges of cells from being changed. Here's what I'm trying to protect:
- Several columns have formulas that auto-populate
depending on entries in other cells.
- The first 15 rows contain 'headers' I need to
protect.

THE PROBLEM:
Using the built-in 'Protect Worksheet' feature kills the ability to collapse an Outline, which I need the users to be able to do. (15 rows of headers collapses into 1, to make it easier to work with.)

THE SOLUTION:
I think the answer probably lies in using the "Worksheet_Change" VB function... But I am completely lost as to how to use the code. (VBA newbie...)

I have created a Named Range that contains all of the cells I need to protect. I want to pop up a messagebox if the user tries to change the values in any of the protected cells, and then move them one cell to the right when the click OK.

Can any of you VBA gurus out there help a fellow out?

Thanks!

Scott