Zoom and scroll image

I'm evaluating the technical issues involved in the development of a digital(ized) document archive with Filemaker.

The simple idea is to make a database of scanned documents.

Each page is stored in a container field on a record.

I want the document browsing (zoom in-out, scroll,...) to be the most quick&comfortable possible for the user.

Zooming and scrolling trought the FM interface is too slow (require too many mouse movements and clicks...)

The solution I've found is to present the user the full page. When the user clicks somewhere on the page then FM zoom into the selected area.

Zoom is performed like this: there are two layouts: full page and zoomed.

The zoomed layout presents the container field enlarged to 2 or more times the size of the window.

On the zoomed layout some global text field are placed over the page.

When the user click on the full page he clicks an invisible button that activates a script.

The script go to the zoomed layout and select a global field.

The selection of the field causes the automatical scroll of the window to the field.

Trought the proper displacement and activation of global fields the "zoom-in" is achieved.

Any idea on how to do that better (maybe with a plugin) ?

Thank in advance for any help.