Hide the running application window from the bar

[fanoI]

Hy, I use Mediaportal an htpc application that runs fullscreen on my secondary screen in my primary screen there is always

this annoying bar on my application bar until Mediaportal is terminated...

See the image for better explanation:

There is a way to hide that "button" whatever-is-its-name with an autoit script?

It's really unuseful too.. it not has the normal windows functions as for example firefox bar (Restore, Move, Resize..., Close)

Thanks for the help,

fanoI