This can be accomplished with <Data<Filter<Advanced Filter.

The criteria range would look like this:

A B C
1 Date Date Blanks
2 =10/1/2008 <=10/31/08
3 =ISBLANK(C15)

Where C15 is the first cell in your Date Column.

Assuming the above criteria are in cells A1:C3, you need to select exactly
that as your criteria range.

Good luck,

Tom