Referencing 0 generated from IF(isna(Vlookup) formula
 

Hi,
I am trying to in compare a parts list from new warehouse we acquired to
determine if any of the parts are already listed in any of our 7 existing
warehouses, so I am attempted to use the below formula to in effect "whittle
down" to just the part #'s that have no match.
=IF(ISNA(VLOOKUP('New Warehouse List'!A2,'Warehouse
#1'!$B$5:$B$8507,1,FALSE)),0,VLOOKUP('New Warehouse List'!A2,'Warehouse
#1'!$B$5:$B$8507,1,FALSE))

In this approach I end up with a "Warehouse #1 matching list", then on a
seperate worksheet, I enter =IF('Warehouse #1 Match'!A2=0,'New Warehouse
List'!A2,0)

This gives me a Warehouse#1 No Match list, which I can run a new VLookup of
Warehouse #2 against this list generating an additional matching and
non-matching list, hopefully until I end up at Warehouse #7 with only a few
non-matching part #'s that I have to load into the system...

The problem is once I've got my non-matching list for Warehouse #1, and move
onto the VLookup for Warehouse #2, the system ignores the 0's that are
created in the Non-Matching list, and I start with the whole new inventory
list, and not a reduced one, even if there are 300 partnumbers less from the
first VLookup... Any ideas????