compare excel workbooks php mysql

Hi I need to compare share holder / trade data and do this online using php and mysql. The interface does not need to be fancy. Must be able to upload for example the month of Jan 2010 and Feb 2010 and compare the data. And pull general reports. e.g. Highest share holders, new share holders, shares that was sold (amounts) + directors are not allowed to trade - be able to check for this... Then let's say the new month is March, be able to compare the new month with the previous month. I want to upload thes excel docs in csv format to the database... There are macros for excel that can do this but it "struggles" to compare data when they are on different cells... I will setup the mysql database on my website under a subdomain. Please let me know the cost and I need a working solution by 9 March if possible. Many thanks