I've seen the mutator... It's not of much use though. Try searching the modsquad site for the d/l. The weapon you want to use a scope on (sniper rifle) already has one. The IG enhanced shock w/scope is a lot of fun, but not available in regular play anyway. Putting a scope on the snotgun won't help you much... lol!
If you wanted to do this without a published, distributed, auto-downloaded mutator (like using your own script) - It would be a cheat, IMO. Either the whole server has it available, or only the llama..
FWIW, I've seen that you can could change your FOV on some servers, at one time (I think it needs to be enabled by the admin now??) that can give you a bit of zoom-like ability. In case you were wondering, that's cheating too, IMO.
Some IG servers I play on have an auto-death zoom, complete with a broadcast message something like "player X has died from attempting to zoom the enhanced shockrifle". They usually leave the server right away when the cheat doesn't work and the rest of us rag on him...