Actually, yes. I forgot that in CVI 6.0 there was a custom control that was added that is a palette for working with graph cursors. (You can find an example under cvi\samples\userint\custctrl\graphcursors\) This palette allows you to zoom in a new way by positioning two cursors, selecting them (using the select button on the palette), and then zooming to the area confined by the two cursor positions. Take a look at the example program and see if that will be an acceptable way for you to zoom.
Best Regards,
Chris Matthews
National Instruments