How do I connect Internet from a laptop using USB modem to a Galaxy S3, or directly USB modem(data card) to S3 for internet connection?
Best guess at real intent of question:
Answer 1: (based on your two options)
Your best approach would be to setup the Laptop as a WiFi hot-spot. It is already working, and you will still be able to use the laptop at the same time. This will require some knowledge of how to do this (for Windows or Linux ?) on your laptop.
To connect the Galaxy S III directly would also require an additional OTG USB cable, and would be a higher drain on the S III's battery.
Answer 2: (looking at other solutions)
A portable WiFi router, either 3G or 4G, would more easily provide Internet access for both the Laptop and Galaxy S III. It is much simpler to setup, and some models would even support using the USB modem you already have. It also has its own battery, for longer Internet time between charging.