Instead of using say, in B1: = VLOOKUP(A1,Sheet2!A:B,2,0)

Use an " =IF(ISNA(VLOOKUP(...)),0, VLOOKUP(...))"
error-trap construct to return zeroes for any non-matches instead of #NAs.

For example, you could use in B1:

=IF(ISNA(VLOOKUP(A1,Sheet2!A:B,2,0)),0,VLOOKUP(A1, Sheet2!A:B,2,0))

Downstream SUMs, etc will now work ok.
--
Rgds
Max
xl 97
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GMT+8, 1° 22' N 103° 45' E
xdemechanik <atyahoo<dotcom
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"Sailor" wrote in message
...
Excell 2002

I am using numerous VLOOKUP functions (including the "FALSE" option)
accross
a row to extract exact values from the same range, which may or may not
contain the look-up value. I then want to sum accross the row to give me
a
running total. The problem is that VLOOKUP returns "#N/A" when an exact
match is not found; which then returns a "#N/A" error in the sum function.