Assuming you're on CR8 or better, if you right click your field, and select the hyperlink tab, you can activate that field to open another file or website when clicked upon.
Save a copy of your report at it's lowest level in your chosen format (i.e. with the drill down open), and point the hyperlink at this file, then both CR and Adobe Acrobat will open this file when the field is clicked.
Naith