You want Vlookup, as in:

=vlookup(PO#,Sheet1!A:B,2,false)

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Regards,
Fred


"Rafa" wrote in message
ups.com...
I have two columns in one sheet (PO# and Invoice#), I have another
column with the same PO# in different rows, i want to return next to
this PO# that Invoice #.

Somebody knows how to perform this, thanks.