[inigma]

What version of Excel?

As the spreadsheet owner, you can lock cells, columns, and rows with a password. Go to "format cell" then make go to the "protection" tab. Then go to Tools/Protection and protect the doc and it will protect cells that are marked locked. You can even protect the whole doc (the default) and then select a group of cells and unprotect, securing the whole document, but still allowing others to update the cells you specify.

I knew that official MS certification for MS Excel course that I paid $70 USD for would come in handy someday.