There are a bunch of SetExtents Methods you could look into.
I would get the current view's extents, increase the coordinates slightly and then set them as the new extents.
get a view reference:
view = app.ActiveView
There are others. Look at the View Object methods in the help.
Thank you for your reply. My intention was to use an Expedition internal zoom function (if there is hopefully one). I want to avoid the required licensing call, because it takes relatively long. The zoom function will be heavily used, therefore it is not acceptable to have a long response times.
Not sure what I was thinking in my post above. For some reason I thought you were asking about DxDesigner. The methods I refer to are for that, not for Expedition.
Other than what was said by Andrew I don't have more to add.