Such a mod will be very easy to make using OBSE.
It gives you the GetActiveMenuSelection function, which while in the magic menu returns the highlighted spell, and it gives you the OnKeyDown and IsKeyPressed3 functions.
So something like
Begin Menumode 1022 if OnKeyDown if IsKeyPressed3 set spell to GetActiveMenuSelection if spell spell.Disable endif endif endifEnd
should get you working...