Cognos 11.1 Bar Chart zoom

[Neo310]

Hello, i have a bar chart (visualization) with a drill through linked.  The user is trying to click on a particular bar to get the drill through to work but b/c of the varying amounts some of the bars are so tiny he cannot click on them.  He can use the filter functionality but that is cumbersome.  When he uses his mouse wheel to try to zoom in, it zooms in horizontally and not vertically.  So the bar is still tiny.  Is there a way he can zoom in vertically so it's easy for him to drill through?