One problem you will have is that the answer is positive for 1, 2, 3, 8
and 9.  So if you want a formula that calcs when it moves from negative
to positive, you may need to do a few steps.

Assume  data A1:A9
B1 enter =SUM($A$1:A1) and copy down the column - creates a running
total
C2 enter =IF(AND(B1<0,B2>0),ROW(),)   checks to see when it changes
from negative to positive.  Creates 0 if the situation doesn't exist,
and the row number if it does.
Sum column C to get the answer

Here is an example
ftp://members.optusnet.com.au/Files/cellchange.xls

Matt

Here is a simple user-defined function; call it with =POS(A1:A10) for
example
Function Pos(myrange As Range)
 myflag = 0
 mysum = myrange(1)
 mycount = myrange.Count
 For j = 2 To mycount
  mysum = mysum + myrange(j)
  If Sgn(mysum) = -1 Then myflag = 1
  If myflag = 1 And Sgn(mysum) = 1 Then
    myhold = j
    Exit For
  End If
 Next j
 Pos = myhold
End Function

best wishes