Grabbing specific lines of HTML from a web page using C#?

I am a novice where C# is concerned and am looking for a bit of instruction. There are a few specific things I would like to know how to do to automate a few laborious tasks I have in my office.

We have a few internal forums which we use for various reasons, which up until now have become a mess. The pages on said forums do however have a structure so I am looking to get a script up together which can access specific lines on specific pages of said forums and export the data contained on those lines to a text document.

For example I want to access web address http://ift.tt/1CM2BhY and within the html source, I know that on lines 35-47 I have tracking information which needs to be exported and the code will do that.

Once I have an idea of how that is structured I shouldn't have an issue writing the rest of the bits I need but I'm really seriously foxed on this :( ANy help would be greatly appreciated.