Is it possible to setup a query to give a run total

Let us say we run a query and get the result below:

Date Quantity
12/1/2003 10
12/2/2003 5
12/3/2003 6

What I would like to do is to set up a third calculated field in the query as follows:

Date Quantity Run Total
12/1/2003 10 10
12/2/2003 5 15
12/3/2003 6 21

I know this could be easily achieved this in a report but I do not want to do this. I want to display the result in a combo box instead.

Thanks for any suggestion.

There's 2 ways to do this here:
http://support.microsoft.com/default.aspx?kbid=138911