Hello there!! (My first post here!)

I'm not a programmer. I know basic C, but am a total newbie when it comes to Quake C. I run an event called the , which uses variation of a Quake1 CustomTF called . We're currently doing a little 'code housekeeping', and I would LOVE to introduce a new type of grenade - the 'smokescreen grenade'.
I don't know if any Guru has programmed such a thing, or even if it's possible, but here's the idea: A gren that throws a cloud of smoke which is opaque (non-see through). The purpose of this gren is to be thrown in open areas to give players cover from sniperfire. Throw, after 3 seconds it explodes , 1 sec as cloud forms, 5 secs total cover, 3 secs till it clears. You can't see inside the cloud from the outside, maybe it's slightly (10%?) transparant. Can this be done? Is this possible? The closest thing I can think of is the gas grenade used by spies in TF, just need the cloud bigger, and opaque.
Someone on irc mentioned that it could use the same method as the pyro 'fire' to create a non-see through 'ball of gas' effect.
I know inevitably it will be thrown indoors as well, and I'm not sure what to do about that. It needs to be big enough to give *some* cover from snipers in open areas (eg the bridge in 2fort5), but somehow not turn the inside of the base into a big mess. Solutuions include making it so people can only carry one, making them really expensive, or even make it so they won't work unless theres a 'sky' directly above ...(?)
Anyway, these issues can be solved later, the main thing now is the actual effect.
Can it be done?
OneManClan