The import can be done like this:
initialData = Import[pathToFile, "Data"]
Now you have a list of pairs in initialData
:
{{IP-8,19500.},{IP-10,34200.},{IP-12,54700.},{IP-14,81900.},{IP-18,161500.},{IP-20,214000.},{IP-22,278700.},{IP-26,442100.},{IP-28,543100.},{IP-30,653000.},{IP-32,782100.},{IP-36,1.09*10^6},{IP-38,1.25*10^6},{IP-40,1.46*10^6}}
As for part 2, I don't understand what you want. You've introduced a bunch of variables without explanation. What is a "section"? What's the "selected data".