This function is not available in the 3-D view.
To do so click the symbols 
and 
or select the desired operation out of the menu 'view'.
The more accurate the area that is interesting for you is in the middle of the window while zooming the more often you can click 
without the area leaving the window.
The menu item view|zoom heavy is very useful to zoom in a special detail quickly. After selecting the menu item the mouse pointer becomes a magnifying glass with which you click the area that shall be enlarged.
With view|make very small you undo this enlargement.
You will not be able to change the zoom anymore if you have fixed one or both scrollbars.