Accessing Webcam Through MATLAB Code

I would like to access an external Webcam (USB). The command I am using is 'imaqhwinfo' but it seems like it can only find the built in one, and not the external connected through USB.

output=

    InstalledAdaptors: {'gentl'  'gige'  'matrox'  'winvideo'}
        MATLABVersion: '8.1 (R2013a)'
          ToolboxName: 'Image Acquisition Toolbox'
       ToolboxVersion: '4.5 (R2013a)'

[Amardeep Singh]

hey! perhaps you are getting this window, i need a Gige adaptors for 2012a , if you have can you please tell me from where to install? or from where to get them.

[Walter Roberson]

Before R2014a, the Gige adapters were supplied with the Image Acquisition Toolbox.

See though http://www.mathworks.com/matlabcentral/newsreader/view_thread/301039, especially for R2011 timeframe.