How do I copy a formula from a group of cells to another group of cells
without excel editing the formula?

For example, I want the exact same formula from one group copied to another
group - as is - without any changes to it at all. For example, I am using
the formula ='10U'!A2 in one cell and want to go down 15 cells and have that
exact formula pasted there. When I do that, excel automatically changes the
formula to ='10U'!A16. I know I can copy from the formula bar, but what if I
want to do this for a large number of cells? It would take me forever. Help!