Not sure how to build the form any idea's

[Pyrotecnix]

OK here is what I have going on right now. Currently I'm trying to build a excel spread sheet into a dynamic form via php. The results are basically questions and are stored each week so for one section they may be asking how many visitors, employee's , etc.. now some of these values that are being entered are going to be used in another question per-say but the result may come from other values that were already submitted so these questions would not be shown in the form that needs to be made later on. The form I'm having trouble with is the initial form to help generate the formula's for these different questions. So what I was going to start doing was have it list all the questions with a check box next to the question if the formula for said question was something like add these two questions and the divide by this set of questions or a whole number then it would display a list of questions for adding together and the get the total from that set and then do a expression afterwards like adding, subtracting, multiplying or dividing. So I was thinking I should list like a set of buttons I think in the beginning. What is the first task at hand Totaling, Adding, Subtracting, Dividing, Multiplying and then when they click on this it would refresh the page and bring up a box that lists all the different questions for them. Then saving the values as which ever button they clicked and once they do this. Then they could either click on say a more button which would pass the values as a array back to the page and continue on or they could click submit and pass the values into a db field as a formula but this is my first concept and would like to know if there may be a better way of doing it.