Put this at the script top somewhere:
Hotkey, $1, customHotkey


Put this at the bottom. What this does is when you press 1 real fast, it will send 1. But if you hold it for 2 seconds (t2) it will send !1 (ALT+1):
customHotkey:
	KeyWait 1, t2
	Send % Errorlevel ? "!1" : "1"
	KeyWait 1
Return