Hi Kevin,
The easiest way to zoom back to the origin is to disable paging:
chart.Axis[StandardAxis.PrimaryX].PagingView.Enabled = false;
In order to zoom in to a specified range you can use the Zoom in method of the paging view:
chart.Axis(StandardAxis.PrimaryX).PagingView.ZoomIn(new Nevron.GraphicsCore.NRange1DD(0, 1), 0.001);
Hope this helps - let us know if you meet any problems or have any questions.