F4 function that locks the cells issue

Hello
I require a bit of help with the F4 function that locks the cells.
As on the example spread sheet

I have filled in the data on G11 with the cell E11 locked value.

When I copy the cell G11 across along row 11, the cells populate fine with the function and all is well

Now with G12 (all the way to G400) , is there a easier way of getting the cells locked (like =F12-$E$12 and =F13-$E$13) as i am having to lock the value manually

Thank you
Veer