There's no scan "button" on the skins yet... we have to wait for a skin that supports it.. I have tested it only by changing the code of a button on a skin.
For the TV plugin, you must configure it in winamp first, without RR.
This is the plugin: http://www.winamp.com/plugins/details.php?id=138360
in Winamp, you should go into preferences and "Input", then select the TV plugin and hit "Configure", you should select your webcam in the device box, then select input pin="preview" and output="thin frame", don't worry about any errors you get during this setup phase. At last on the "scan" tab you should select where to save your "channel" files (it should be an empty folder) and then click add manually to create the "channel" file for the webcam. once you do this and set RR to use that folder of the "channel" file, you should be able to get the TV screen in RR to open the view of your webcam.