I tried to put your idea into:
StrSqlInvExt = "SELECT INVCEHED.CUSN65, INVCEHED.DTIN65, OEP845L2.TENT45, DELADDS.ONAM45, DELADDS.OAD445, TRIM(DELADDS.OAD545), OEP040L1.SVIA40, INVCEHED.INVN65, INVCEHED.CUSO65, SQP608L1.ICAT08, OEP040L1.CORD40, INVCEHED.ORDN65, min(case when INP40.TLNO40='1'...