drew
By default all cells on a worksheet are "locked" when Tools>Protection>Protect
Sheet is enabled.
To lock just a few cells, hit CRTL + A which selects all cells, then
Format>Cells>Protection>uncheck "locked".
Now select the cells you want locked and Format>Cells>Protection>check
"locked".
Now Tools>Protection>Protect Sheet. Provide Password if desired.
Note: sheet protection passwords can be easily broken, so the "locking" is for
protection from inadvertant overwrite only.
Gord Dibben Excel MVP