There are 2 ways to doing that:
WAY A. Ship directly from seller to your own shipping company
You need to add your shipping company's address in the note column of every product in your shopping cart
Advantage: Save local shipping cost compare to WAY B
Disadvantage: Seller cannot mark your custom label on the parcel, if your shipping company fail to identify or lose your parcel, you bear all the risk
WAY B. Act as normal order; After all products arrive at our warehouse->Submit to ship to your own shipping company in China
Advantage: We can combine and repackage your product and mark the necessary label so your shipping company can identify your parcel
Disadvantage: Need local shipping cost from our warehouse to your shipping company.
As our warehouse handling cost is also inlcuded in local shipping cost.
It will be a little expensive than normal. Check the shipping rate here