Multiple Deliveries into Single invoice

Dear all,

I am trying to club multiple Deliveries into Single invoice. iam facing below message....

Number of foreign trade data         0000000007           0000000008

Division                                         10                        20

Customer purchase order number  Export House-1       Export House-2

Reference Document Number        Export House-1       Export House-2

Requirment is , For Export , can combined multiple deliveries with diffrent product(Divisions) in single invoice. to avoid the cost.

But , SAP system is not allowing this,

I have tried by making VTFL , Header and Item level copying requirments Blank. still iam getting the same message.

Please sugget.

Many thanks,

Raj