You need to take your car to a professional to pinpoint the problem. There are other possible problems. I doubt that it is your head gasket.
It might be you radiator, it can mix transmission fluid with coolant. Check transmission fluid level or signs of discoloration.
Make sure they find the problem before spending a lot of money on something that might not solve your problem.
[Edited by vinamg on 01-14-2001 at 04:49 AM]