Schedule count by shift and date...

Hello again,
Here s the deal.... I have a table that describes a weekly schedule of a call center dpt.
For each agent there are several lines, each of one describes by task for an agent (emp id is the key) the start date, the stop date, the start time, the stop time, the assigned task (including breaks...) and the agents team during a day.
As a result there are many lines that describe an agents day shift.

What i am trying to do is to count the number of agents that are assigned to each shift for each team...

I believe that what i need is the earliest assigned task start time and the latest assigned task stop time for each agent for each day....and then count it with date and team (emp class) criteria


any ideas on how to retrieve this out of my original data?...

Thank you all in advance

thank you for your reply but this is not what i want...
let me give you an example...
for employee with id 200791 at Aug 13 2012 his first assigned task starts at 12:00 am (cell L2) and his last assigned task ends at 08:00 pm (cell N8). Therefore his shift is 12:00 to 20:00 and that counts for 1 schedule at Aug 13th for shift 12:00-20:00.
So what i need first is to find for every unique id and for the date range i have (13/08/12-19/08/12) the earliest start time (minimum value in column L with criteria the id and the date) and the latest stop time (max value in column N with criteria the id and the date).
Then I will find all the unique shifts and count them for every different date (... and that is the easy part )

I hope i made my task more clear...

Any other ideas?
please for your help!