Formulas for referencing data from another sheet

To begin with, this may be somewhat of an involved project and needs some visual explanation, so I have attached the workbook that I will be using as an example, so please take a look. I have a call report sheet named “Dec-08” and I would like the data from “Dec-08” to automatically populate a call frequency report, which will be on another sheet named “Call Frequency”. On “Call Frequency” I would like the cells in column A to look at column D on “Dec-08”, find the GIS #, then populate column A in “Call Frequency” with that #. But if the same # shows up more than once on “Dec-08”, I would like it to only be populated one time on “Call Frequency”. From there “Call Frequency” columns B:Y will look at what is in column A on “Call Frequency” and populate those cells accordingly from referencing the “Dec-08” sheet columns E, F, and L.
Column B on “Call Frequency” will be populated with the corresponding account name from “Dec-08” column E.
Columns C:Y on “Call Frequency” will be populated with the total hours of time spent at that particular account from “Dec-08” column L. If more than one contact , column F, was seen on the same day, the sum of those hours will shown for that day on “Call Frequency”. (May Be Tricky???)
Columns Z and AA are all ready to go.
If this doesn’t make sense then please let me know, otherwise thank you so much for your help, I owe you big!
Lukas

I appreciate the response SHG, but I am not that familiar with pivot tables and if that would work the way that I want it to. If you wouldn't mind clarifying, I would appreciate it. Does anyone else have another way of accomplishing this; I am open for any other suggestions or ideas?

Thanks,
Lukas

I have achieved the basic concept by using a macro to create a pivot table, which I think shall suffice for now.....thanks for your help and the suggestion of the pivot table.

Lukas