problem on record to different account

hi expert,

my script problem:

*WHEN ACCOUNT

*IS 81110020

*REC(EXPRESSION=%VALUE%/3,ACCOUNT=COSTCENTER+ACTIVITY.IS_ACCOUNT)

*ENDWHEN

in this record i want to store into ACCOUNT : GSIP_200065001020

but the result show is store in ACCOUNT : COSTCENTER65001020

then i change :

*REC(EXPRESSION=%VALUE%/3,ACCOUNT=COSTCENTER.ID+ACTIVITY.IS_ACCOUNT)

now result show is store in ACCOUNT : GSIP_2000ACTIVITY.IS_ACCOUNT

any idea on how to store in ACCOUNT : GSIP_200065001020??

thanks.