Help with R1C1-formula

I think I got it, though it's not in R1C1 format

Sub torrdo()
Dim lastrow As Long

lastrow = Sheets("lajittelu").Cells(Rows.Count, "b").End(xlUp).Row

Sheets("huuhaa").Range("m1").Select
    Do Until ActiveCell.Row = lastrow
        ActiveCell.Formula = "=IF(" & ActiveCell.Offset(0, 2).address & ">1,SUMPRODUCT((huuhaa!G1:G" & lastrow & "=lajittelu!" & activecell.offset(0,-6).address & ")*(huuhaa!H1:H" & lastrow & "=lajittelu!" & ActiveCell.Offset(0, -5).address & ")*(huuhaa!K1:K" & lastrow & "=lajittelu!" & ActiveCell.Offset(0, -2).address & ")*(huuhaa!O1:O" & lastrow & "=lajittelu!" & ActiveCell.Offset(0, 2).address & ")*(huuhaa!M1:M" & lastrow & ")),SUMPRODUCT((huuhaa!G1:G" & lastrow & "=lajittelu!" & _
        ActiveCell.Offset(0, -6).address & ")*(huuhaa!H1:H" & lastrow & "=lajittelu!" & ActiveCell.Offset(0, -5) & ")*(huuhaa!K1:K" & lastrow & "=lajittelu!" & ActiveCell.Offset(0, -2).address & ")*(huuhaa!M1:M" & lastrow & "))-SUMPRODUCT((huuhaa!G1:G" & lastrow & "=lajittelu!" & ActiveCell.Offset(0, -6).address & ")*(huuhaa!H1:H" & lastrow & "=lajittelu!" & ActiveCell.Offset(0, -5).address & ")*(huuhaa!K1:K" & lastrow & "=lajittelu!" & ActiveCell.Offset(0, -2).address & ")*(huuhaa!O1:O" & lastrow & "=lajittelu!" & ActiveCell.Offset(0, 2).address & ")*(huuhaa!M1:M" & lastrow & ")))"
    ActiveCell.Offset(1, 0).Select
    Loop
    
End Sub