Hello TL,
There is not a built in function within CVI to interact with 3rd party applications. You would have to use Windows SDK functions to capture a handle for the active window (QuickCam window), and then send a keypress to that window. You may also need to use SDK functions to navigate through the menus of the QuickCam application in order to copy the displayed image if Ctrl-C or some other comparable keypress combination does not work.
I would suggest looking at the functions EnumWindows/GetWindow and SendMessage.
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winui/winui/windowsuserinterface/windowing/messagesandmessagequeues/messagesandmessagequeuesreference/messagesandmessagequeuesfunctions/sendmessage.asp
Wendy L
LabWindows/CVI Developer Newsletter