security help

Do you mean shared as in, "In Excel I selected 'Share workbook'" or shared as in, "I am going to email a copy of this to someone else"?

In either case, first set up your worksheet. By default, all cells are locked. Select the cells where you want to allow changes, and then go to Home, Format, Lock Cells to un-highlight the lock icon.

If it's easier to this the other way round, select the whole sheet and unlock them as above, then select the ones to lock and follow the same steps.

Then go to Review, Protect Sheet (I think that's it in 2007, I may be mistaken on the exact clicks).

Then go to Review, Share Workbook, if that's what you have in mind.