LT03 transaction problem

Hello friends

I have an issue

I am creating transfer order for delivery in WM ,

I have 3 main storage types defined

921 for putaway : i.e material taken in warehouse but not put in rack.

001 Rack storage type

916 Material booked against delivery. After Post Gossds Issue the stock is removed from WM.

Now My issue is that if material is in 921 and no stock is available on the rack, system proposes material from 921 which is not desirable as dynamic temporary storage bin is created till the stock is filled up in rack.

Can we restrict LT03 using any user exit to pick only from storage type 001 (rack storage)??

This will help in avoiding any un-necessary confusion while picking.

Thanks and Regards

Kartik