Need help with graphics for a cool add-on

[Hitman]

I am already since a long time ago researching and writing an article about the procedures for getting firing solutions in real life U-Boots and have been able to get incredible high quality info in the process. I can now explain how germans got the AOB of their targets (With a purpose made wiz-wheel attached to the scope !!!) and want to do a mod for SH3 that allows you to have at last that wiz-wheel on your hands (Since unfortunately I can't put it in the game) if you are ready to print and cut a bit, yet I need to make some modifications in the scope graded reticle to add some stuff for the easiest use (Following a picture I have of a real view through the scope).

Can someone tell me which file contains that reticle or how to add new stuff there?

Any help much appreciated

P.S. 1: If someone has an idea on how to put moveable (Rotatory) graphics in the scope screen contact me and we can try to build it in-game

P.S. 2: I'm finishing the article in spanish, when it's ready it will be translated to english and be available publically