Hi Pecoflyer,

Here's the string to assist. Sorry I didn't provide this detail earlier:

Assume a single row with columns A1 thru U1.

10, 12, 1, 2, 0, 3, 6, 7, 18, 20, 0, 3, 4, 30, 10, 12, 11, 0, 2, 1, 7

A1 = 10 and U1 = 7.

The formular should work Left-to-Right starting with U1 and, in this case the answer would be 7+1+2 = 10.

Regards.