Finding where data comes from for transaction ck86_99 - really need help!

How can I find the following data?

It is all hidden via OO code and I ain't got a clue on how to find it:

-Transaction: ck86_99

-enter values on the initial screen and press enter.

-A screen of relevant data is displayed.

-Then press 'Show all items' (shift+F2)

This then displays values like Variances, contractor cost etc. and their respective amounts and I want to know where these values come from?

I've tried debugging but I couldn't understand what was going on?! I've spent hours on this and I am getting nowhere -can somebody please help?

Please help!!!