help from aggr script in load statement

[#1]

hi

i have 1 table with order(numordine) and order items (ccoar)

NUMORDINE	CCOAR	DTCRE	DTCTB
ORD1	ART1	20140606	20140607
ORD1	ART2	20140606	20140608
ORD2	ART1	20140705	20140706
ORD2	ART3	20140609	20140611

i need calculate from load script the avg difference from (dtcre and dtctb group by for ccoar) group by for any numordine !

how can I make a group by in another group by in only load statement?

in load script i can't use with aggr function..

Aggr(DISTINCT

    AVG(

        if (

            Aggr(DISTINCT DTCTB,CCOAR,DTCTB)>0 and Aggr(DISTINCT DTCRE,CCOAR,DTCRE)>0

            ,

            Interval(date(date#(Aggr(DISTINCT DTCTB,CCOAR,DTCTB),'YYYYMMDD'),'YYYYMMDD') - date(date#(Aggr(DISTINCT DTCRE,CCOAR,DTCRE),'YYYYMMDD'),'YYYYMMDD'),'d')

        )

    )

    ,NUMORDINE

)