This formula works:
`ActiveCell.FormulaR1C1 = "=SUM(R[-14]C:R[-1]C)"`
it returns `=sum(c1:c14)`

This formula does not work:
`ActiveCell.FormulaR1C1 = "=SUM(R[-" & nrows & "]C:R[-1]C)"`
It returns `=SUM(C14:C1048576)`

I have this statement

```
Dim nrows as Integer

```

why does the formula with the nrows variable not work