VBA R1C1样式有变量 怎么写

'分类汇总小计行
Sub c5()
Dim x As Integer, m1 As Integer, m2 As Integer
m1 = 2
For x = 2 To Range("A65536").End(xlUp).Row + 2
If Cells(x, "A") = "" Then Exit Sub
If Cells(x, "C") <> Cells(x + 1, "C") Then
m2 = x
Rows(x + 1).Insert
Cells(x + 1, "C") = Cells(x, "C") & "小计"
Cells(x + 1, "H").FormulaR1C1 = "=sum(R[m1-m2-1]C:R[-1]C)"
Cells(x + 1, "H").Resize(1, 4).FillRight
Cells(x + 1, "I") = ""
x = x + 1
m1 = m2 + 2
End If
Next
End Sub

这一句该怎么改Cells(x + 1, "H").FormulaR1C1 = "=sum(R[m1-m2-1]C:R[-1]C)"

Cells(x + 1, "H").FormulaR1C1 = "=sum(R[" & m1-m2-1 & "]C:R[-1]C)"

cells(行号, 列号) 例如：cells(2, 3)，就是第2行第3列的那个单元格。