If it is coming from the front of the tranny, check the dipstick; that is the most common spot, and it will look like it is coming from other places because the windage from driving will push it towards the back of the tranny. To fix this, i put a fairly generous amount of gray silicone around the dipstick before I put it in, and then let it sit and dry without fluid in it for awhile before I started it up again. That hasn't leaked since I did that. There is also some white glue stuff, that if i can remember the name of it, i will post it, that I used on the trans pan gasket, and it doesn't leak anymore either. Anyway, good luck. Leaks on the C4's are common, but it is hard to figure out where they are coming from.
Dave