Automatic Billable effort hours calculation

Hi,

I need help to construct a excel spreadsheet for my project to track billable effort hours which would auto-update based on daily entries.

Brief:
i have 6 members in a team including me. We have a Project(say named FLEX) & we certain effort hours budgeted for this project (say for e.g 800). These 800 hours are allotted under various WBS (work breakdown structure)codes like D01, D02 & so on until D15 which totals to 800. Now everyday one or all persons in my team will work on this project & book their hours under respective WBS codes. (the hours booked by persons may be haphazard, like someone books 2 hours under WBS code D15, other person on the same day books 4 hours under the same code, some other person may book 4 hours under D10 & so on..No restriction to limit the hour bookings on a particular day)

i have to maintain a sheet which captures the entire project hours, date-wise, day by day- person-wise & mapped with respective WBS codes.
Also, it should show me how many hours under a particular WBS code are remaining "as on date", i.e.=TODAY() to enable me to track the hours. Also, if possible the sheet should flag an alarm (in terms of colored cell or otherwise) when any particular WBS code hours are about to exhaust ,say 10 hours before.

Pl help & provide me with a excel sheet or guide on formulaes.

Thanks,
Mahesh