paste a forumla and copy with a macro

Here is my problem. I have data in columns A:C however the number of rows
will differ each time.

I need a macro that will paste a preset formula eg. (=sum(A1:C1)) into cell
D1 and drag it down to the last cell which contains data in the previous
columns?

Thanks in advance

Sub addFormulas()
Dim rng as Range
With worksheets("Sheet1")
set rng = .Range(.Cells(1,3),.Cells(rows.count,3).End(xlup))
End With
rng.offset(0,1).Formula = "=Sum(A1:C1)"
End Sub

--
Regards,
Tom Ogilvy



"Chris_t_2k5" <Christ2k5@discussions.microsoft.com> wrote in message
news:610CA6D2-146C-440A-9FB4-752C94CD94AD@microsoft.com...
> Here is my problem. I have data in columns A:C however the number of rows
> will differ each time.
>
> I need a macro that will paste a preset formula eg. (=sum(A1:C1)) into
cell
> D1 and drag it down to the last cell which contains data in the previous
> columns?
>
> Thanks in advance