Should be an inspection port on the trans somewhere IMO. You could look in to see if everything is covered in oil and go from there.
After reading your post, it actually reads as if you are seeing a increase in RPM but the car does not accelerate accordingly or at the same rate. If you are sure the car is revving without moving Id say you are on the right track. If the car is revving without cause but moving accordingly, Id say you have an issue in your IAC, TPS or etc.
Hope this helps.