How would I calculate exponential regression?

It would help if you had a specific example.

Even though this is not my area of expertise, I searched Google under the key words "exponential regression" to get these possible sources:

http://mathbits.com/MathBits/TISection/Statistics2/exponential.htm
http://people.hofstra.edu/stefan_waner/realworld/calctopic1/regression.html
http://www.bettersolutions.com/excel/EUN147/NO837118332.htm
http://zweigmedia.com/RealWorld/calctopic1/regression.html

In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search.

I hope this helps. Thanks for asking.