Here's a creative way to protect cells in an Excel worksheet so that other users can't make changes to them:
Select the cells you want to protect. (It's a good idea to make a note of the cells you protect in case you need to remove that protection later.)
On the Data menu, click Validation, and then click the Settings tab.
Set the following restrictions: In the Allow box, click Text Length; in the Data box, click between; in the Minimum box, type 10000; and in the Maximum box, type 50000.
Click the Error Alert tab.
Make sure the Show error alert after invalid data is entered check box is selected. In the Style box, click Stop.
If you want a title to appear in the title bar of the message or in the Office Assistant balloon if the Office Assistant is displayed, type the text in the Title box. If you leave the Title box blank, the title defaults to Microsoft Excel.
If you want to display your own text for the message, type the text in the Error message box, up to 225 characters. Press ENTER to start a new line in the message. If you don't enter any text in the Error message box, the message displays the following: "The value you entered is not valid. A user has restricted values that can be entered into this cell."
Excel displays the message only when a user types data in the cell.
To remove data validation settings, select the protected cells, click Validation on the Data menu, and then click Clear All.