Shift: +
Ctrl: ^
Alt: !

Code:
#IfWinActive, World of Warcraft 
~+MButton:: 
{
ControlSend,,{Shift down}{MButton down}{MButton up}{Shift up}, ahk_id %wowid1% 
ControlSend,,{Shift down}{MButton down}{MButton up}{Shift up}, ahk_id %wowid2% 
ControlSend,,{Shift down}{MButton down}{MButton up}{Shift up}, ahk_id %wowid3% 
ControlSend,,{Shift down}{MButton down}{MButton up}{Shift up}, ahk_id %wowid4% 
ControlSend,,{Shift down}{MButton down}{MButton up}{Shift up}, ahk_id %wowid5% 
}
return
Pretty sure you can remove the line for wow1 because you will be pushing the buttons down and so will AHK... so it will be doing it twice.