Match/Vlookup function in excel

General information for the business: marketing agency
Description of requirements/functionality: This is a one off job.

We have a list of names organised by dates in an excel tabs (3 sample columns below):

01.01.08 - Lee - 5
01.01.08 - Lee - 2
01.01.08 - Emma - 2
01.01.08 - Emma - 2
01.01.08 - John - 3
01.01.08 - John - 3
01.01.08 - Mark - 2
08.01.08 - Lee - 4
08.01.08 - Lee - 1
08.01.08 - Emma - 7
08.01.08 - Emma - 6
08.01.08 - John - 9
08.01.08 - John - 1
08.01.08 - Mark - 5
08.01.08 - Emma - 2

We'd like a formula that matches 2 conditions - date and name - then return the value of all matches in a SUM.

E.g.

01.01.08 + Lee, the value returned should be 7.
08.01.08 + Emma, the value returned should 15.

Notes:

Must work for any number of appearances of the names - Lee could appear under 01.01.08 once or ten times.

We actually have two tabs, so not only does it have to match 2 conditions (date and name), add the returned value, it also has to do it for two tabs and sum everything up.
OS requirements: Windows
Extra notes: