You can find the original webcam holder at http://www.thingiverse.com/thing:31171.  
I wanted to position the webcam in the upper corner of the printer to get a nice view of the print bed. For this I needed two additional beam types: one turning the screw holes by 90° and thus allowing a "change in direction" in the beam construction (directly attached to the frame attachment in the picture), and one L-shaped beam allowing to screw a regular beam in on the top (attached near the camera in the picture).  

Publishing since those two new beam types might be of help to others too.  

Mix and match the available parts for your individual situation.

The pictured holder uses two regular beams, one 90-deg-beam and one L-beam on top of the frame and webcam attachments, attached in the following order:

• Frame attachment
• 90-deg-beam
• regular beam
• L-beam
• regular beam
• webcam attachment

If you want to replicate this setup, you should know what to print ;)