Hi,
I couldn't find the same example (488mfc). Did you get it from the web?. Anyways...
As you can see this is a linker error. This means that your source was properly compiled. The linker has to resolved the undefined functions. In this case, all the GPIB function are unresolved. To solve this you need to include the library that contains the functions.
For the MS C++ interface I believe that an object file is included. This file needs to be added to your project's settings. If the functions where defined in a dll, you would need to add a .lib file to your project's settings.
The following link has some information:
Language Interface: 32-bit Microsoft Visual C/C++
DiegoF