MT4 csv job

Need a solution for exporting csv Date/time & OHLC. (MT4)

Script (or whatever method necessary) will need to automatically save the last most recent 500, 1hr OHLC bars of all subscribed pairs in Marketwatch, onto individual csv files. 

Hence, the data of each new bar, at the top of each new hour, will be automatically saved onto the top of its own csv file when MT4 is open - and the bar at the end of the csv file, 500 bars ago, will be deleted. In short, there should always be 500 bars of the most recent data on the csv's.