You need to tell us what you know about R/S and what exactly your problems are. I'm thinking this would be easier to do in Matlab than Excel, since you'll likely want to store your data in an array and that way you can easily make the "window" you use for R/S and slide it over the data. There are other methods you can use to get the Hurst exponent - one of which is using something called "structure functions" (which are moments of differences). If you are so inclined, you can find out about these structure functions in the following paper (and others):
Kiyani, K., Chapman, S. C., and Hnat, B., 2006, Phys. Rev. E
, 051122 (Link
You also shouldn't post your email address, as you're likely to get spammed.