Hi Andy,
I moved you post back to .NET Forum. Would be handy to know what Version of CR SDK you are using also, kind of important to know also....
So you are looking for a trigger event or click event on the CR viewers Zoom button?
Have you tried clicking on the Lightning bolt on the viewer properties?
And rather than guessing as to why you want to use Java to do the same or why you need to use Java or why you can't use the Viewers Event, please explain what the end result is...
In the ViewZoom event you could hook into your Java script that way, I think....
Don