Extract data from multiple worksheets in multiple workbooks into one master summary file

Hi,

I am looking for a way to consolidate 48 workbooks (one for each month in a four year period). Each workbook represents a month, and has between 28-31 worksheets in it depending on the month to represent each day. In each worksheet there is a price given in 15 minute intervals over a 24 hour day, or 96 entries starting in cell c6 down to c101. I am trying to find a way to consolidate all of these worksheets into one master workbook. Not only that, but I need to average the prices from 15 minute intervals into one hour intervals.

In summary, I have 48 workbooks containing 28-31 worksheets in each with data listed in 15 minute intervals that needs to be consolidated down to 1 workbook with 4 worksheets (one for each year) listed in one hour intervals. Is there anyone who can help point me down the right path or help me out?

Cheers!

sample.xlsx

The file is too large (over 8 mb) so I have attached a sample. In each workbook, there are two irrelevant worksheets in the beginning, plus a worksheet for each day labeled by the number of the day (these are what I care about). There are also irrelevant worksheets called price corrections that I do not need. The only worksheets that are relevant are the ones labeled by day, for example for the first day of the month the worksheet would be titled "1". Each workbook is labeled consistently: 20xx-xx_BES.xls (year-month_BES.xls)In the sample I have attached, it includes just two days. The entire file can be downloaded here http://www.ercot.com/mktinfo/services/bal/2009/index relatively quickly.