VS 2010 - Statement That Reads Through A Text File Till The End While Pulling Out 3 Different Matched Items

Im trying to come up with a do while statement that reads through a text file till the end while pulling out 3 different matched items, then writing those matched items to ascending spots in an excel file, and then creating a bar graph according to the saved data. Sounds complicated but...I have the program reading the text file, pulling out the first iteration of all three, writing them to an excel file, and I have it even graphing them the way I want it to. The only thing I havent done before (and which is probably the easiest), is creating the do while statement so it keeps searching line to line for the three interactions of what im looking for and writing them to ascending spots in the excel file.

Right now my code works like this, which is perfect for pulling out the first 3 and creating a graph, I just inserting a do while and a rowindex + 1 variable.

vb Dim alines() = System.IO.File.ReadAllLines("C:deviceinfo.txt")
Dim amatch As String
Dim muvalue As String

[CODE]................

I have a feeling in order to pull this off, I do not want to use the, "ReadAllLines" option and possibly want to put the text into an array.

And do something like: if lines.count > 0

But im not familiar with how arrays work in VB, and more specifically what the syntax is. The other tricky thing I am trying to add is an if statement that adds to a variable (such as i) everytime a line is added to excel so the program will write to ascending lines. I was trying to have the it work with the do while statement but pretty soon realized that if I did: i = i +1. Everytime it went through the loop then the data was going to be on random lines corresponding to their place in the text.