[WoW] Mouse moving in video feeds

Hi

I have a window layout for World of Warcraft which displays a scaled down version
of my healer's window inside my tank's window. I now want to be able to control my
healer completely through this video feed.

However there is a problem: when using right click for turning the healer, the cursor
is not fixed. This means that while I turn my healer, the curser will eventualy leave
the feed region. This makes this way of controlling the healer quite useless.

Is there any way to make this work or is this a fundamental limitation of
video feeds / rerpeater regions?