Macro:Minimap Ping

From Dual-Boxing Wiki

Minimap Ping was used before patch 2.4.2 to allow the use of AoE spells while multiboxing. AoE spells were targetted by clicking on the minimap on 1 client so that the other clients would use this location to cast the AoE spell to. However, this isn't possible anymore in the current WoW client.

See post regarding the change for more information:

"Yes, allowing AddOns to target spells via the minimap ping was not intentional and was fixed. 
AddOns may not directly cast spells or change targeting." [1]

See also [2]