Modding Replay System - Tib Dawn Remaster

I got the idea to try and create a mod for the replay system of Tiberian Dawn Remastered and I guess to that extent also Red Alert Remastered if the mod can easily work on both games. I just want the current unit/structure that is being produced/built by each player to be shown on screen as the game progresses similar to how SC2 does this (with maybe additional changes in the future) but I must be blind or dumb because I can't for the life of me find any part of the code that relates to the replay system. Can someone point out where this is or if anything already exists or just help a brother out in anyway? 

Much Love