How do I get a cell to = another cell in another workbook?
Have both files open.
In the file where you want the the formula select the cell where you want
the the formula and type an = sign (don't hit enter). Navigate to the other
file and select the cell you want to link to. Now hit enter.
Excel will automatically add the file name to the link and when you close
the source file Excel will automatically include the path. This can save you
a lot of typing!