Production order from sales line


I am using AX2009. I am creating Production order from sales order lines. Sales order lines → Inquiries → Production. It opens production order create form. Here site, warehouse fetching from sales lines but I want to change it to WIP warehouse. Site will be same only warehouse will get changes for ex. Site S1, sales line having warehouse W20, on Proudction order create form it should fetch W30. If I change it on the same form then it will refelcts same in sales lines also. If I change in production order detials form then it will break linking of sales order from referance. Is there any solution or any modification in the program. Please help!