Here is what I made to block mine.

#SingleInstance, force
#NoTrayIcon ;Add ; before # to disable.
#Persistent

LButton::
WinGetActiveTitle, ACTW
CoordMode, Mouse, Window
MouseGetPos, XP, YP, Window
YM:= % YP
If YM > 10 ;How far to block from the top of the window.
{
Hotkey, LButton, Off
Send, {LButton Down}
KeyWait, LButton, Up
Send, {LButton Up}
Hotkey, LButton, On
Return
}
Else
{
BlockInput, Send
Sleep, 250
BlockInput, Off
}
Return