Create Reports from CSV -- 2

We sell a subscription product but due to our product options (monthly, every two months, cancellations, etc), we're unsure who should get our product each month (without manually going through each and every customer in the system to check if they are due the product) - we need an automated way to do this. Upon the new month starting, we have a CSV of our entire customer base, the product that they have purchased, and relevant information (purchase date, renewal date, cancelled, product type, etc) What we need is a way to pull reports from this information to determine who is due to get the product this month, and their details from the report. The reports would be: Small Product Customer Large Product Customer Small Product Customer - Custom Large Product Customer - Custom Rules, for example: - Some customers are active, and are due the product. - Some customers are active, but get the product every two months, and received the product last month, therefore they do not get the product this month. If they did not receive the product last month, they would get it this month. - Some customers have purchased within the previous month, and cancelled, therefore they would be due the product. Etc. What we need to do is have a report created, somehow, perhaps using Excel, or a PHP script that can be run against the CSV (of all customers), to extract the relevant customers who are due the product this month, as per the rules. We would run the script/report, against the csv, monthly, to make our 'run sheet' for the product dispatch. I can provide a sample of data, and a sample of the rules that need to be run against the data.