Hello Brent,
Thanks very much for the interest.
From a brief look at the C2D's specifications on Nord's website ( http://www.nordkeyboards.com/products/nord-c2d ), the C2D has a USB output, so you could probably just connect it to your computer via USB (instead of using real MIDI ports/cables), first making sure that the C2D's USB is driver is installed on the computer ( http://www.nordkeyboards.com/downloads/products/nord-c2d-organ ). Most USB-capable keyboards will present their USB connections to the computer as MIDI ports, so if you launch Hauptwerk *after* making sure that the C2D is connected and powered up then hopefully you will see an entry for the C2D on Hauptwerk's 'General settings | MIDI ports | MIDI IN ports' screen. You need to tick that entry in the left-hand ('Console MIDI IN') column, click OK, and follow the other instructions in the 'Quick-start' section in the main Hauptwerk user guide (on the Help menu in Hauptwerk) to load the St. Anne's organ and use right-click auto-detection to map the virtual keyboards to your C2D's physical keyboards.