Yep. Refer to it the way you would refer to any other column on the query builder. So, if column 2 reads "Expr1:[AskMe]" which generates an "Enter Parameter" dialogue, column 3 can read Expr2: [Expr1] * 2 and will evaluate to <whatever you entered> * 2.
As far as I know, though, you only get to enter such parameters once, when the query is opened, so Expr1: in the above example will be whatever you answer for every record in the query, and so will Expr2. If you want a different value for each record, you'll need to get it through a control.
--Expressive Mac