Here's a basic script that allows you to focus the view on a specific location, such as a point on the surface of a model.

// Create a point picker.
var pointPicker = moi.ui.createPointPicker();

// Wait for the user to pick a point.
pointPicker.waitForEvent();

// The user picked a point.
if (pointPicker.event == 'finished') {

    // Set the 3D viewport's target to the location of the picked point.
    moi.ui.mainWindow.viewpanel.getViewport('3D').targetPt = pointPicker.pt;
}