Using AltGr as standard modifier key in emacs

[Shahab Shahsavari Alavidjeh <zzgraph@gmail.com>]

Hi there

While that's my first post here, I'm going to introduce myself a little
bit, and I think this introduction might be relevant to my question
here, I'm Shahab Shahsavari Alavidjeh (simply everyone can call me Shibi
if that's too hard to pronounce) and I'm using emacs for my day to day
tasks (as a writer and translator) for writing and organizing my
tasks. Well I'm not a software developer or an emacs expert by any
means, therefor my questions or requests may seems dumb.

Well I'm an Iranian and a Persian speaker, which leads us right to the
problem, while emacs has great support for UTF-8 and complex script
languages (like Persian) and there is a well maintained quail input
method package for farsi (thanks to Mohsen Banan
http://mohsen.1.banan.byname.net/) there's a huge problem with that (and
as I already reviewed the code for hebrew, arabic and even latin-alt
input methods this problem exists there too) There is no implementation
for AltGr key or ISO_Level3_Shift key in elisp. So every input method
re-implemented a different modifier key and bind the third or forth
level modification to that. (in persian that key is "\" in hebrew that
key is "`" in latin-alt that key seems to be "_" in latin-post the key
is ",") which IMO is a very inconsistent way of implementation.

But waht is my question?

is there any way to work around this problem and assign a modifier key
to "Right Alt Key" on keyboard which is accessible through elisp
customization? something which I can assign a character (for example á
to (kbd rightalt-a))?

Why I don't simply use my D.E. input method support and keyboard layout
switcher instead?

I'm currently using it, that's my best option right now, but then I
should switch keyboard layouts whenever I want to run a command in emacs
or even when I want to save a file to disk.

I appreciate any answer which can help me to get it working.

What I'm using right now is

GNU Emacs 24.5.1 (x86_64-redhat-linux-gnu, GTK+ Version 3.16.6) of
2015-09-14 on buildvm-10.phx2.fedoraproject.org

Thank You
Shahab