Plotting complex data to a line graph

Hi guys,

I am having trouble creating a line graph with the data set below.

I have a spreadsheet of 1000+ lines of projects to be completed over the next three years.

What I am looking to do is work plot that expenditure in a linear fashion across the months in which the project will be running.

So for example project a is scheduled to run for 3 months starting in November 2011 and finishing in January 2012 and it will cost $9. That is three months of work costing $9. Now I want to spread that out over the period and have $3 for Nov, $3 for Dec and $3 for January. Project B runs from January 2012 to March 2012 and cost $3. I want that spread out with $1 for Jan, Feb and Mar.

How can I plot a line graph with each month totals if all I have is the information below:
Start Finish Months from start to finish Months from current date (1/9/11) to finish Cost per month for remaining months
1-Apr-10 2-Apr-13 36 19 $ 8,170,078.06
1-Apr-10 2-Apr-13 36 19 $ 8,170,078.06
17-Jun-10 24-Oct-12 28 13 $ 5,967,491.93



Thank you very much for your help