In layman's terms, I am trying to perform the following:

Assume:
- Column A contains a list of Account numbers (that may contain duplicates)
- Column B contains a list of Dates (that may contain duplicates)
- Column C contains a list of Amounts

I need to SUM the vales that meet both the criteria, and return them to
another cell.

So for example:
Column A Contains: 4444, 5678, 5678, 1234, 4444
Column B Contains: 14-Jan-06, 23-Jan-06, 23-Jan-06, 01-Feb-06, 14-Jan-06
Column C Contains: $100, $300, $500, $250, $130

So, under the heading January 06, the correct values to return would be:
$230 for account 4444
$800 for account 5678
and account 1234 would return $0 as it is outside the month of January

I am familiar with MONTH, DATEVALUE, SUMPRODUCT, SUM, SUMIF, VLOOKUP,
HLOOKUP, LOOKUP etc. but this problem is driving me nuts...

Appreciate any assistance from you experts out there...Thanks!