Option Explicit
Sub test()
    Dim i
    i = 2
    Do Until Range("A" & i) = ""
        Range("A" & i).Offset(0, 3) = Range("A" & i) + 1
        Range("B" & i).Offset(0, 1) = Range("B" & i) + 1
        i = i + 1
    Loop
End Sub