A "Send here" option it is like to the "Send to..." but send the window to the current workspce. This option will avaible only when you click on window icon in the panel. I have implemented this in libxfcegui4, here: http://unstable.it/lash/sendhere.patch there is the patch Thanks
Created attachment 1356 The patch :)
Unfortunately we're currently phasing out use of libnetk in libxfcegui4 in favor of using the standalone libwnck library. Probably the right thing to do here would be for you to file a feature request with the libwnck developers.