Average & Copy To Another Workbook

I have two workbooks. I need to average some data and pass that
information to the other workbook through a macro.

The information I need is average by Month by Hour. The first workbook
has rows of the month and day (1-Jan , 2-Jan , etc…) for a whole year and
columns of 15 minutes times (7:00,7:15:7:30,7:45, 8:00, etc…).

I need that stored in the second workbook. This workbook will be initiating the macro.

So I need to get average time by Month by Hour (Jan @ 7:00 = < ? >). I was trying to think of a loop that would cycle through the first workbook and populate the
second but I haven’t really programmed in excel before.