To actually alter the anchor of that "tooltip", you'd have to replace the whole Update function of the LFG frame.
An easier solution would be using :SetClampedToScreen(true)
http://wowprogramming.com/docs/widge...lampedToScreen
As for what Game92 suggested, when it comes to overlapping, the easier solution for that would be using :SetToplevel(true)
http://wowprogramming.com/docs/widge...me/SetToplevel