Which version of Corel are you using??? I am currently using 9, and just upgraded from 7 about 6 or 8 months ago. I can't recall, but I believe that 7 exproted to .eps, and I just confirmed that 9 does. You may not have installed all the export filters when you installed your program. Insert your original Disk 1 and go through like you are going to install the program again. I believe there is an option to upgrade (I could be mistaken, it has been a while). Go through your setup choices and somewhere in there is a filters selection. Be sure that .eps is selected. I have found that you can never have enough import/export filters, it is worth the space on the drive to include all of them, even if you don't think you'll ever use any of them.
As I don't have my install disks here, I am just going on memory, if something is incorrect, I appologize, but this should get you pointed in the right direction.