global c = 0

$WheelDown::            ; Down/Sleep/Up usage.
key := DownSeqkeys("2","3","4")
send {%key% Down}
sleep, 20
send {%key% Up}
return

DownSeqkeys(k1,k2,k3){   ; 3 keys rotation, 8 second reset.
    static s:=0, t:=8000
    (A_TickCount-s<=t && c<3) ? c+=1 : c:=1, s:=A_TickCount
    Return k%c%
}