To clarify, you are not allowed to use the same license of CorelDRAW on two different computers at the same time. You are however allowed to install your copy of CorelDRAW Graphics Suite on a second computer such as a laptop if your primary computer is a desktop machine, at the condition that both copies are never used at the same time. You are not allowed to install it more than twice on devices that you use, so don't put CorelDRAW on every computer in your company for example if you don't have the appropriate number of licenses.
There are some exceptions to this for certain countries, and to get all the details, you should read the End User License Agreement that you get when installing the software, from the About menu in the application or from the Corel web site. Here is the first sentence of the CorelDRAW Graphics Suite X4 EULA:
Unless you have a written agreement with Corel providing for additional Use, the below agreement gives you permission to install and Use one (1) copy of this Product on one (1) computer or electronic device at any given time as set out in more detail below.
UPDATE: I need to add a little disclaimer here. Please don't ask me if this specific scenario is legal or not and if your usage is possible or not... First, I am not a lawyer, and second, it is up to you to make sure you comply with the EULA ;-)
Gérard