One way is to name the specific cells you want to enter the data into.
Select the second cell of the bunch of cells of a group and hold down Shift
and click on each cell in the sequence you want to enter the data, ending
with the first cell. Now, while the first cell is still selected, name the
range of selected cells with an appropriate name given the data to be
entered. For example, Costs, Expenses, Supplies, etc.
Select a name from the name box from the Name Box and see the cells of the
named range are highlighted. Enter the data in the first cell and hit
either Enter or Tab and continue through the range until back to cell 1.
Left or right arrow out of the named range. (Up or Down also)
So now if someone hands you a list of Expenses to enter, you select Expenses
from the Name Box and enter the data. Same with the other named ranges.
If you go with sheet protection method that may work well for you if you
always have the same sequence of data to enter in the unprotected cells and
the data is in that sequence also.
HTH
Regards,
Howard