How do I restrict orders based on category - oscmall

[Guest]

I installed the oscmall mod but it is not doing what I want.

What I have done is that each category is a store. When a customer put the item in the cart, I want the cart to divide and show it by store. When they checkout, they should have charges - shipping, handling, etc for each store.

Or, allow them to only shop from one store at a time but all stores display in the category area. How do I do that