When you launch an Autodesk product in VDI - if you are prompted by the FlexNet License Finder you will want to select Specify the License Server System and enter GCCADNLM.
If you get prompted to choose either a Single-user or Multi-user license type, you will always want to select Multi-user. Once Multi-user is selected it should not ask you for any other information (like a serial number for example).