Keith,

I don't think you are going to get this in one select. You can get it in two though;

SELECT * FROM dmlError WHERE ErrorCode = "120" INTO CURSOR Temp NOFILTER

SELECT ... FROM DataPPO LEFT OUTER JOIN Temp ; 
             ON DataPPO.Fed_taxId + DataPPO.Tax_sufx = ;
                Temp.Fed_taxID + Temp.Tax_sufx ...

you will need the indexes on the conactentation of the two fields.