report filter variables?

Hi all.  Just wondering if it's possible to define a formula column in a report using a filter value specified by the user as report runtime? Can you reference a runtime filter value by name somehow in the formula column formula?  Are the report filter values given by the user at runtime even stored in variables?  I know you can reference them as 1 and 2, etc, in the advanced filter logic dialog, but trying this in a formula column doesn't work.