A good way of figuring out references etc. is to record a macro in the workbook and then look at the completed macro to find the commands required to solve the problem. For example in the following macro I had values in the first four rows of column A. Starting from A1 I used <End><down> to get to the last row, moved down 1 and entered the max formula. The resulting macro is:
Sub Macro1()
Selection.End(xlDown).Select
Range("A5").Select
ActiveCell.FormulaR1C1 = "=MAX(R[-4]C:R[-1]C)"
Range("A6").Select
End Sub
A little experimentation should help to figure out how to make that work for any case.