Arthur,
You can access it both ways as 'attached' i.e. Loggin in the logmein OR unattached client, depending upon your Hamachi configuration.

https://secure.logmein.com/welcome/documentation/EN/pdf/Hamachi2/LogMeIn_Hamachi2_GettingStarted.pdf
Please refer to page 10 for installation instructions in the above link.

Start Dragon on your laptop, you will see the dragon taskbar at the very top of the screen. Connect to your office computer, access AC, you should be able to dictate.