I sell items from different dropshippers, and each one has a different postage rate. I have the Royal Mail mod installed which is working fine for the items I have in my store, as they are sold by weight. But I also deal with another dropshipper who charges £3.00 for the first item them £1.00 for each additional item. Is it possible to set my cart up so the appropriate shipping method is automaticaly chosen?

I am new to all this and only just getting my head around modding the files