Send double-click with Autohotkey

I'd like to remap the middle mouse button to double-click using autohotkey.

A simple remapping (4th mutton -> middle button) worked fine using XButton1::MButton but I couldn't find a way to remap a button to send a left-button doubleclick.

I've already tried MButton::LButton 2 and MButton::LButton & LButton but those didn't work (apparently this syntax is only used in different AHK statements but not in remappings).

Nevermind, found the answer:

MButton::Click 2

This will specify which button you want to press:

+LButton::
send {LButton 2}
Return

LButton is left click MButton is middle click RButton is right click