Formula1 = "=SUM(RC[-3]:RC[-2])" ' HOW TO MAKE ALWAYS REFER TO COL A ??
Cells(i, colNum).FormulaR1C1 = Formula1


R[1]C[0] means the next row (relative) in the same column

but there's also an absolute wsay with RC style: R1C1 means the cell in
column 1 and row 1 (A1 cell)

So R[2]C1 means the column 1 (absolute) but 2 rows below (relative)
the [] means relative
without it means absolute