AHK - simulating Fn key shortcut - autohotkey

Question

I would like to build an AHK script that will press Fn + D and Fn + G for me when executed.
Unfortunately, after checking the "key history" from an an AHK script where I enabled "KeybdHook", it appears that my keyboard's Fn key doesn't trigger any key action when pressed.
Should I give up all hope?
Unnecessary context :
On my 65% keyboard, Fn + [Key] shortcuts are pivotal for replacement of various missing keys, as well as for changing various keyboard settings.
In particular, RGB settings are changed using Fn + D and Fn + G — and, annoyingly, they reset to a default, ugly rainbow every time I restart my computer, instead of a more subdued RGB setting which I prefer. The script I am trying to build would change these settings automatically on startup (until my brain grows large enough to comprehend QMK, my keyboard's RGB software)
Thanks in advance. I fully expect bad news.

Answer 1

QMK has a good diagram of how keyboards work:
+------+ +-----+ +----------+ +----------+ +----+
| User |-------->| Key |------>| Firmware |----->| USB wire |---->| OS |
+------+ +-----+ +----------+ +----------+ +----+
When you press a key on your keyboard the QMK Firmware inside the keyboard interprets the key presses and creates a set of keycodes of what exactly to send down the USB wire to the OS.
If you configure QMK Firmware to say that Key(1,1) is the letter "a", whenever you hit Key(1,1), it will send the letter "a" (scancode 0x04) down the USB wire.
There are some keys and that combinations which don't get sent down the USB wire at all. For example, Fn keys are typically used to switch between virtual "layers". This means that if you configured it, Fn + Key(1,1) could now send the letter "z" (scancode 0x1D). Now, when you hit Fn + Key(1,1), it will send the letter "z" (scancode 0x1D) down the USB wire. It will not send the Fn key, because the Fn key only matters to QMK firmware, and not the OS.
When you press the Fn + D keys, the QMK Firmware interprets this as change RGB Setting. Even though you may be a part of pcmasterrace, the OS does not know anything about RGB keyboards and lighting. Also, there is no RGB scancode in the USB HID protocol defining "change RGB". Therefore pressing the Fn + D keys sends nothing down USB to the OS.
Since Change RGB isn't happening on the OS, and it only exists inside your keyboard, Autohotkey cannot send the right set of keystrokes to replicate the functionality. The only way to make changes to the default settings in the keyboard is to make and flash your own custom QMK firmware.

Answer 2

As the others stated, the Fn+D and Fn+G functions are totally handled inside the keyboard package, with no information passing to or from the PC side, making it impossible to readily insert a PC script routine in between.
However, keyboard mechanical switches are perhaps the simplest circuit in the world; with a couple of jump wires and a microcontroller (MCU), you can simply override any finger movement. Now, if that MCU is handled correctly, it may be controlled by PC-side software such as AHK, allowing you to accomplish your aim.