Getting Record Status From A History Table

Dear All,

I have a MAIN table which stores the most recent info of a record with
following details:

Unique_Ref_Num|Status|Dept
1 |6 | 1

and a second table called history which records changes in the main table

HistoryID | Status | DateStamp
1 | 1 | #22/10/2007 09:00#
1 | 2 | #22/10/2007 09:01#
2 | 1 | #22/10/2007 09:05#
2 | 2 | #22/10/2007 09:06#
1 | 2 | #22/10/2007 11:00#
2 | 3 | #22/10/2007 15:00#
1 | 3 | #22/10/2007 16:00#
2 | 2 | #22/10/2007 16:10#


Where Status 1 = Open, 2 = Allocated and 3 = Closed.
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I want to get the count of number of queries which are not closed
(outstanding) at any point in time.

Example: (with a time parameter)
Input | Result
22/10/2007 17:00 | 1
22/10/2007 16:05 | 0
22/10/2007 14:00 | 2

I want to achieve this with just 1 query (not by using one query within the
other) b,coz I want to further use this query from Excel VBA (write through
Excel VBA and not store the query within Access)

Any help will be greatly appreciated
--

Many Thanks
Baapi
:confused: