Quantity getting increased in case of reference

D/ Friends,

In our scenario, weu2019ve to create the second contract (e.g. type QC2) with reference to the first contract (e.g. type QC1). But here when user increases the quantity in second contract (i.e. QC2) more than the reference contract (i.e. QC1), system is allowing increase the quantity. But we want that system shd not allow to increase the quantity of the second contract. How can we handle this thru std config, w/out the help of ABAP? Have I made my requirement clr?

Thanks.