AutoHotkey (EU keyboard): how to remap LCtrl while keeping AltGr

I searched past questions, but I haven't found a solution to switch LAlt with LCtrl (or CapsLock with LCtrl) while preserving completely AltGr, that corresponds to Ctrl+Alt (or maybe LCtrl+RAlt?).

This is the closest question, but I cannot use Registry, I have limited privileges.
Switch Ctrl and Alt with AutoHotKey without messing up the Alt-Tab switcher?

Also related:
https://code.google.com/p/uawks/issues/detail?id=2

I'm using either of these simple scripts:

LAlt::LCtrl
LCtrl::LAlt

Second one:

LCtrl::CapsLock
CapsLock::LCtrl

Whenever I press AltGr with any other key, something get stuck and I have to press randomly Alt, Ctrl until I can write again. If I use the second script, CapsLock gets activated!

My keyboard is Swiss and I have a lof of keys with a third symbol, therefore I need often AltGr, remapping each one would not be a clean solution.

Update

I just found out that the issues with AltGr are completely solved by adding the following line at the end of the two scripts previously posted, but I don't understand why this is happening.

<^>!::RAlt

Why is the remapping of AltGr as RAlt ALONE still producing the effect of a regular AltGr?