If you have a network license at your company, you can borrow the license from the license server. Please note that if you borrow a license, a best practice is to borrow it the exact time that you need because you are taking a license from your company's license pool.
1. If you borrow a license on your laptop until December 25th, 2012, you can connect to the laptop on the network at any time before the 25th to return it.
2. If you don't connect the laptop on the network by the 25th, the server will return the license automatically on December 26th, 2012.
3. The Autodesk software on the Laptop will stop working on December 26th, 2012.
Here is an visual instant replay of the process using Civil 3D 2012:
1. Click on About Civil 3D 2012 > Product Information.
2. Click on Borrow License button.
3. Select the borrow date period.
4. There is a confirmation of borrowed license.
5. To return, the license, just go back to About Civil 3D 2012 > Product Information.
6. On the license server, if you Perform Status Inquiry, you will get the word linger in the status.
7. The license will be returned in 235260 seconds.
Please check out this importance post about setting an options file on the license server to limit what you can do on the client (laptop) computers:
NOTE: I know for a fact that License Borrowing in not available in Autodesk Simulation CFD 2012.