thanks...it appears that your group by has aggregation levels that are more granular than the order # but your requirement is to filter orders that have only one unit sold. this means that the total of NUM_SALES will be on the lowest group level and hence your filter in the report will not work as you want.
so that you don't undo the existing group levels that you already have in your command, what you may to do is to add a subquery that returns the num sales at the order # level...add the following to the end of your select statement...there may be errors as I don't have your db to test against...note though that I've aliased the tables in the subquery using _TWO except in the case of the last line in the WHERE clause as.
(SELECT SUM("OEIND94_TWO"."IDSHP#")
FROM "SN4M"."ASTDTA"."OEIND94" "OEIND94_TWO"
INNER JOIN "S1047N4M"."ASTDTA"."ICPRT1" "ICPRT1_TWO" ON
"OEIND94_TWO"."IDPRT#"="ICPRT1_TWO"."IAPRT#"
WHERE "OEIND94_TWO"."IDCOM#"='001' AND
"OEIND94_TWO"."IDDOCD" >= {?FromDate} AND
"OEIND94_TWO"."IDDOCD" <= {?ToDate} AND
"ICPRT1_TWO"."IARCC4"='FIN' AND
"OEIND94"."IDORD#" = "OEIND94_TWO"."IDORD#"
) AS NUM_UNITS_BY_ORDER_NUM