Holding down LMB in minimized window

[kolonisatie]

I am trying to make an working script which will hold down my Left Mouse Button in Minecraft. I want to be able to toggle the script by pressing control + arrow up. (When I first press it it has to start holding down my Left Mouse Button, and when I press control + arrow up again it has to release my left mouse button)
I currently have this:

^Up::
Toggle = !Toggle
if Toggle
ControlSend, , {LButton Down}, Minecraft 1.12.2
else
ControlSend, , {LButton Up}, Minecraft 1.12.2
return

but is does not work at all. Can anyone help me?