Well it can’t be done with nero for a start.
If it’s the original release of WCIII (v.1.0) the protection used is securom new and you should be able to copy it successfully with any of, in alphabetical order, Alcohol, Blindwrite, CD-Mate, CloneCD, Discjuggler or Gamejack.
If it’s a later release (say v. 1.4+) the protection is securom 4.8x and it will be more difficult to make a working copy. Essentially, your options are a twinpeak copy (made either using blindwrite or by patching an image made in clonecd format with either alochol or clonecd) or a copy requiring either autoplay or RMPS emulation made with blindwrite or alcohol respectively.
Have a look through the tutorials and let us know if you have further problems after reading through the applicable tutes.