Partial Delevery

Hi there, I would like to know if any of you guys have solved this problem by Coding or functional In Dropshipment Sales order ( after the PO is created) I wanted to create multiple DO and then one invoice) the system doesn’t allow me to do partial deleviry. just for information the item which am delevering also has a batch no - lot tracking . If there is coding required where do I do that Rgds