I will finish my walktrough soon. The covert operations missions can be found in the nintendo 64 rom, however officially you can't play them, but with the help of nyerguds, I managed to play almost all of them. There are only two covert operations missions, which aren't in the nintendo 64 rom. Deceit and Eviction Notice, but you can find for example the PSX spec ops missions. More details here:
You can simply edit the rom with a hexadecimal editor. Basically you need to replace all occurance of SCG30EA to the desired mission code, which can be found in the txt file above.
I post some of my videos. I use cheese tactics. That means engineer rush, early push, proxy base or something like these. I use them because I haven't seen them in c&c walktroughs on youtube. However, there are many cheese tactics in the starcraft youtube walktroughs.