Originally Posted by
Erzengel
What happens if all you put in is
#showtooltipp Earth Shield
/cast [@mouseover][] Earth Shield
or
#showtooltipp Earth Shield
/cast [@mouseover, help][] Earth Shield
Should ES mouseover if the target is a viable ES target, and take your normal target if there's no mouseover that can be eartshielded.
I remember having mouseover earth shield macros and using the default raid ui in cataclysm, so at one point it worked. Keybind was C. Macro was something along the lines of this:
"/cast [mod:alt, @player][@mouseover, exists][] Earth Shield"
Anyway, i cant check ingame right now, so good luck with your macro. Hope you find a solution