When it comes to running Microsoft Windows Server or Microsoft SQL Server in AWS, there are currently three options regarding licensing:
Simply pay the normal AWS fee for Windows Server instances (on-demand, spot, reserved). These fees are typically more than same-sized instances of other operating systems. See: https://aws.amazon.com/windows/resources/licensing/#launch
See the diagram below for setting BYO licensing for Microsoft SQL Server to AWS RDS. The "Licensing Mobility" has already been worked out between Cornell and Microsoft (and AWS) so selecting "bring-your-own-license" and checking the "I acknowledge..." box should be all you need to do.