Put all the fonts that you have downloaded or copied from one or more CD's, into a seperate folder on your system. Do not put them under the Windows\Fonts folder.
Then, bring up the Font Navigator, that was installed along with CorelDRAW Suite, and have it scan your system for fonts.
From this point on, any font that you want to use, you can drag it from the left panel (uninstalled, but on the disk) to the right panel (installed, ready for use).
You can do this to as many fonts as you want to have running. But one note, here, make sure you have all the patches for X3 installed on your system. If I recall, there was a patch for the Font Navigator and it may be necessary to run the Font Nav properly.
Once you have finished using any font that you dragged over to the right panel, you can drag it from the right panel to the left, thus "uninstalling" the font. You do not want to do this to any critical Windows font. And you want to keep the number of active fonts below, say 400, as the more fonts you have active, the more Windows resources are utilized to manage them (thus reducing the memory for Corel DRAW suite and the speed at which the suite will run at.)
For more information on the Font Navigator, fire it up and click on the Help menu item.