The C330 requires an accessory known as a paramender for close-up work. The paramender goes between your tripod and the camera, and is used to raise the camera by an amount equal to the distance between the taking and viewing lenses. You compose and focus with the paramender set in one position, and then adjust the paramender to make the exposure.
The system actually works quite well, but it isn't as ideal as an RB67.
By the way, the paramender came in a few different versions. If you have a paramender 3 (like I do) you are best off, but the paramender 2 works well too.