
Below 2 steps of 5 minutes you need to perform only once in lifetime then its automation only. From next time once you start mobile hotspot then Raspberry-Pi will get automatically connected to the Mobile WiFi. :)
Step 1 - First time you have to connect Raspberry-Pi to laptop using Ethernet. Please refer this link Access Raspberry Pi from Windows PC using Ethernet or LAN .
Step 2 - Open GUI by taking Remote Desktop. Please refer this link Accessing raspberry pi using Remote Desktop (RDP Client) .
Step 3 - Search for mobile WiFi and Connect Raspberry-Pi to the WiFi. Also Connect Laptop...